Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. TIM is an extremely efficient enzyme involved in the process that converts sugars to energy in the body.

Enzymes are proteins that catalyze (i.e. accelerate) chemical reactions.^[1] In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, the products. Almost all processes in a biological cell need enzymes in order to occur at significant rates. Since enzymes are extremely selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell. Image File history File links TPI1_structure. ... Image File history File links TPI1_structure. ... Proteins are an important class of biological macromolecules present in all biological organisms, made up of such elements as carbon, hydrogen, nitrogen, oxygen and sulfur. ... Triose-phosphate isomerase (TPI), is an enzyme (EC 5. ... This is a calotte model of cyclohexane. ... Magnification of grains of sugar, showing their monoclinic hemihedral crystalline structure. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... It has been suggested that this article or section be merged into Catalysis. ... Iron rusting - a chemical reaction with a slow reaction rate. ... Vapours of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride A chemical reaction is a process that results in the interconversion of chemical substances. ... In science, a molecule is a group of atoms in a definite arrangement held together by chemical bonds. ... In biochemistry, a substrate is a molecule upon which an enzyme acts. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. POOP Cells in culture, stained for keratin (red) and DNA (green). ... In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell, catalyzed by enzymes, resulting in either the formation of a metabolic product to be used or stored by the cell, or the initiation of another metabolic pathway (then called a flux generating step). ...

Like all catalysts, enzymes work by lowering the activation energy (E_a or ΔG^‡) for a reaction, thus dramatically accelerating the rate of the reaction. Most enzyme reaction rates are millions of times faster than those of comparable uncatalyzed reactions. As with all catalysts, enzymes are not consumed by the reactions they catalyze, nor do they alter the equilibrium of these reactions. However, enzymes do differ from most other catalysts by being much more specific. Enzymes are known to catalyze about 4,000 biochemical reactions.^[2] Although all enzymes are proteins, not all biochemical catalysts are enzymes, since some RNA molecules called ribozymes also catalyze reactions.^[3] Other synthetic molecules called artificial enzymes, can also display enzyme-like catalysis.^[4] The sparks generated by striking steel against a flint provide the activation energy to initiate combustion in this Bunsen burner. ... Chemical equilibrium is the state in which the concentrations of the reactants and products have no net change over time. ... Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers, that acts as a messenger between DNA and ribosomes, and that is also responsible for making proteins out of amino acids. ... // A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. ... Schematic drawing of artificial phosphorylase An artificial enzyme is a synthetic, organic molecules prepared to recreate the active site of an enzyme. ...

Enzyme activity can be affected by other molecules. Inhibitors are molecules that decrease enzyme activity; activators are molecules that increase activity. Many drugs and poisons are enzyme inhibitors. Activity is also affected by temperature, pH, and the concentration of substrate. Some enzymes are used commercially, for example, in the synthesis of antibiotics. In addition, some household products use enzymes to speed up biochemical reactions (e.g., enzymes in biological washing powders break down protein or fat stains on clothes; enzymes in meat tenderizers break down proteins, making the meat easier to chew). HIV protease in a complex with the protease inhibitor ritonavir. ... Bacillus stearothermophilus phosphofructokinase. ... For other meanings, see Drug (disambiguation). ... The skull and crossbones symbol (Jolly Roger) traditionally used to label a poisonous substance. ... Fig. ... The correct title of this article is . ... Staphylococcus aureus - Antibiotics test plate. ... Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ...

Etymology and history

Eduard Buchner

As early as the late 1700s and early 1800s, the digestion of meat by stomach secretions^[5] and the conversion of starch to sugars by plant extracts and saliva were known. However, the mechanism by which this occurred had not been identified.^[6] 19th century (or early 20th century) photograph. ... 19th century (or early 20th century) photograph. ... Eduard Buchner (May 20, 1860 -- August 12, 1917) was a German chemist and zymologist, the winner of the 1907 Nobel Prize in Chemistry for his work on fermentation. ... (17th century - 18th century - 19th century - more centuries) As a means of recording the passage of time, the 18th century refers to the century that lasted from 1701 through 1800. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Kinnikuman character, see Meat Alexandria. ... Starch (CAS# 9005-25-8) is a complex carbohydrate which is insoluble in water; it is used by plants as a way to store excess glucose. ... Magnification of grains of sugar, showing their monoclinic hemihedral crystalline structure. ... Saliva is the watery and usually somewhat frothy substance produced in the mouths of humans and some animals. ...

In the 19th century, when studying the fermentation of sugar to alcohol by yeast, Louis Pasteur came to the conclusion that this fermentation was catalyzed by a vital force contained within the yeast cells called "ferments", which were thought to function only within living organisms. He wrote that "alcoholic fermentation is an act correlated with the life and organization of the yeast cells, not with the death or putrefaction of the cells."^[7] Beer fermenting at a brewery. ... Functional group of an alcohol molecule. ... Typical divisions Ascomycota (sac fungi) Saccharomycotina (true yeasts) Taphrinomycotina Schizosaccharomycetes (fission yeasts) Basidiomycota (club fungi) Urediniomycetes Sporidiales Yeasts are a growth form of eukaryotic microorganisms classified in the kingdom Fungi. ... Louis Pasteur (December 27, 1822 – September 28, 1895) was a French chemist best known for his remarkable breakthroughs in microbiology. ... Vitalism is the doctrine that vital forces are active in living organisms, so that life cannot be explained solely by mechanism. ...

In 1878 German physiologist Wilhelm Kühne (1837–1900) coined the term enzyme, which comes from Greek ενζυμον "in leaven", to describe this process. The word enzyme was used later to refer to nonliving substances such as pepsin, and the word ferment used to refer to chemical activity produced by living organisms. Wilhelm Kühne (March 28, 1837 - June 10, 1900), German physiologist, was born at Hamburg. ... Pepsin is a digestive protease (EC 3. ...

In 1897 Eduard Buchner began to study the ability of yeast extracts to ferment sugar despite the absence of living yeast cells. In a series of experiments at the University of Berlin, he found that the sugar was fermented even when there were no living yeast cells in the mixture.^[8] He named the enzyme that brought about the fermentation of sucrose "zymase".^[9] In 1907 he received the Nobel Prize in Chemistry "for his biochemical research and his discovery of cell-free fermentation". Following Buchner's example; enzymes are usually named according to the reaction they carry out. Typically the suffix -ase is added to the name of the substrate (e.g., lactase is the enzyme that cleaves lactose) or the type of reaction (e.g., DNA polymerase forms DNA polymers). Eduard Buchner (May 20, 1860 -- August 12, 1917) was a German chemist and zymologist, the winner of the 1907 Nobel Prize in Chemistry for his work on fermentation. ... Humboldt-Universität zu Berlin The Humboldt University of Berlin (German Humboldt-Universität zu Berlin) is Berlins oldest university, founded in 1810 as the University of Berlin (Universität zu Berlin) by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt whose university model has strongly influenced... Zymase is a enzyme complex that catalyze glycolysis, the fermentation of sugar into ethanol and carbon dioxide. ... This is a list of Nobel Prize laureates in Chemistry from 1901 to 2006. ... In biochemistry, a substrate is a molecule upon which an enzyme acts. ... Lactase is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. ... Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. ... 3D structure of the DNA-binding helix-hairpin-helix motifs in human DNA polymerase beta A DNA polymerase is an enzyme that assists in DNA replication. ...

Having shown that enzymes could function outside a living cell, the next step was to determine their biochemical nature. Many early workers noted that enzymatic activity was associated with proteins, but several scientists (such as Nobel laureate Richard Willstätter) argued that proteins were merely carriers for the true enzymes and that proteins per se were incapable of catalysis. However, in 1926, James B. Sumner showed that the enzyme urease was a pure protein and crystallized it; Sumner did likewise for the enzyme catalase in 1937. The conclusion that pure proteins can be enzymes was definitively proved by Northrop and Stanley, who worked on the digestive enzymes pepsin (1930), trypsin and chymotrypsin. These three scientists were awarded the 1946 Nobel Prize in Chemistry.^[10] Richard Willstätter Richard Martin Willstätter (August 13, 1872 – August 3, 1942) was a German chemist whose study of the structure of chlorophyll and other plant pigments won him the 1915 Nobel Prize for Chemistry. ... James Batcheller Sumner (November 19, 1887 – August 12, 1955) was an American chemist. ... Helicobacter Pylori Urease drawn from PDB 1E9Z. Urease (EC 3. ... Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ... John Howard Northrop (July 5, 1891 – May 27, 1987) was an American biochemist who won the Nobel Prize in Chemistry in 1946 (with James Batcheller Sumner and Wendell Meredith Stanley) for purifying and crystallizing certain enzymes. ... Wendell Meredith Stanley (August 16, 1904 – June 15, 1971) was an American biochemist, virologist and Nobel prize laureate. ...

This discovery that enzymes could be crystallized eventually allowed their structures to be solved by x-ray crystallography. This was first done for lysozyme, an enzyme found in tears, saliva and egg whites that digests the coating of some bacteria; the structure was solved by a group led by David Chilton Phillips and published in 1965.^[11] This high-resolution structure of lysozyme marked the beginning of the field of structural biology and the effort to understand how enzymes work at an atomic level of detail. X-ray crystallography, also known as single-crystal X-ray diffraction, is the oldest and most common crystallographic method for determining the structure of molecules. ... Lysozyme single crystal. ... Albumen redirects here. ... Lord David Phillips is considered to be a founding father of the now expanding field of structural biology and was an influential figure in science and government. ... Structural biology is a branch of molecular biology concerned with the study of the architecture and shape of biological macromolecules--proteins and nucleic acids in particular—and what causes them to have the structures they have. ...

Structures and mechanisms

See also: Enzyme catalysis

Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site. Diagram drawn from PDB 1MOO.

Enzymes are proteins, and range from just 62 amino acid residues in size for the monomer of 4-oxalocrotonate tautomerase,^[12] to over 2,500 residues in the animal fatty acid synthase.^[13] The activities of enzymes are determined by their three-dimensional structure.^[14] Most enzymes are much larger than the substrates they act on, and only a very small portion of the enzyme (around 3–4 amino acids) is directly involved in catalysis.^[15] The region that contains these catalytic residues, binds the substrate, and then carries out the reaction is known as the active site. Enzymes can also contain sites that bind cofactors, which are needed for catalysis. Some enzymes also have binding sites for small molecules, which are often direct or indirect products or substrates of the reaction catalyzed. This binding can serve to increase or decrease the enzyme's activity, providing a means for feedback regulation. Enzyme catalysis is the catalysis of chemical reactions by enzyme molecules. ... Image File history File links Carbonic_anhydrase. ... Image File history File links Carbonic_anhydrase. ... Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid interconversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ... In chemistry, a monomer (from Greek mono one and meros part) is a small molecule that may become chemically bonded to other monomers to form a polymer. ... 4-Oxalocrotonate tautomerase (EC 5. ... Fatty acids are aliphatic acids fundamental to energy production and storage, cellular structure and as intermediates in the biosynthesis of hormones and other biologically important molecules. ... In biochemistry, many proteins are actually assemblies of more than one protein (polypeptide) molecule, which in the context of the larger assemblage are known as protein subunits. ... Phenylalanine is one of the standard amino acids. ... The active site of an enzyme is the binding site where catalysis occurs. ... A cofactor is any substance that needs to be present in addition to an enzyme to catalyze a certain reaction. ... It has been suggested that this article or section be merged with Feedback loop. ...

Like all proteins, enzymes are made as long, linear chains of amino acids that fold to produce a three-dimensional product. Each unique amino acid sequence produces a unique structure, which has unique properties. Individual protein chains may sometimes group together to form a protein complex. Most enzymes can be denatured—that is, unfolded and inactivated—by heating, which destroys the three-dimensional structure of the protein. Depending on the enzyme, denaturation may be reversible or irreversible. Protein folding is the process by which a protein assumes its characteristic functional shape or tertiary structure, also known as the native state. ... In biochemistry, the tertiary structure of a protein is its overall shape. ... A protein complex is a group of two or more associated proteins formed by protein-protein interaction that is stable over time. ... Irreversible egg protein denaturation and loss of solubility, caused by the high temperature (while cooking it) In biochemistry, denaturation is a structural change in biomolecules such as nucleic acids and proteins, such that they are no longer in their native state, and their shape which allows for optimal activity. ... In biochemistry, the tertiary structure of a protein is its overall shape. ...

Specificity

Enzymes are usually very specific as to which reactions they catalyze and the substrates that are involved in these reactions. Complementary shape, charge and hydrophilic/hydrophobic characteristics of enzymes and substrates are responsible for this specificity. Enzymes can also show impressive levels of stereospecificity, regioselectivity and chemoselectivity.^[16] In biochemistry, a substrate is a molecule upon which an enzyme acts. ... The adjective hydrophilic describes something that likes water (from Greek hydros = water; philos = friend). ... In chemistry, hydrophobic or lipophilic species, or hydrophobes, tend to be electrically neutral and nonpolar, and thus prefer other neutral and nonpolar solvents or molecular environments. ... In chemistry, stereospecificity is the property of a chemical reaction that yields different stereoisomeric reaction products from two stereoisomeric reactants depending on the reaction conditions. ... In chemistry, regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions. ... Chemical reactions are defined usually in small contexts (only up to a small number of neighbouring atoms), such generalizations are a matter of utility. ...

Some of the enzymes showing the highest specificity and accuracy are involved in the copying and expression of the genome. These enzymes have "proof-reading" mechanisms. Here, an enzyme such as DNA polymerase catalyses a reaction in a first step and then checks that the product is correct in a second step.^[17] This two-step process results in average error rates of less than 1 error in 100 million reactions in high-fidelity mammalian polymerases.^[18] Similar proofreading mechanisms are also found in RNA polymerase,^[19] aminoacyl tRNA synthetases^[20] and ribosomes.^[21] In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... 3D structure of the DNA-binding helix-hairpin-helix motifs in human DNA polymerase beta A DNA polymerase is an enzyme that assists in DNA replication. ... RNAP from pictured during elongation. ... An aminoacyl tRNA synthetase (abbreviated aaRs) is an enzyme that catalyzes the binding of a specific amino acid to a tRNA to form an aminoacyl-tRNA. The synthetase hydrolyzes ATP to bind the appropriate amino acid to the 3 hydroxyl of the tRNA molecule. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ...

Some enzymes that produce secondary metabolites are described as promiscuous, as they can act on a relatively broad range of different substrates. It has been suggested that this broad substrate specificity is important for the evolution of new biosynthetic pathways.^[22] It has been suggested that this article or section be merged into natural product. ...

"Lock and key" model

Enzymes are very specific, and it was suggested by Emil Fischer in 1894 that this was because both the enzyme and the substrate possess specific complementary geometric shapes that fit exactly into one another.^[23] This is often referred to as "the lock and key" model. However, while this model explains enzyme specificity, it fails to explain the stabilization of the transition state that enzymes achieve. Hermann Emil Fischer (October 9, 1852 - July 15, 1919) was a German chemist and recipient of the Nobel Prize for Chemistry in 1902. ...

Induced fit model

Diagrams to show the induced fit hypothesis of enzyme action.

In 1958 Daniel Koshland suggested a modification to the lock and key model: since enzymes are rather flexible structures, the active site is continually reshaped by interactions with the substrate as the substrate interacts with the enzyme.^[24] As a result, the substrate does not simply bind to a rigid active site, the amino acid side chains which make up the active site are moulded into the precise positions that enable the enzyme to perform its catalytic function. In some cases, such as glycosidases, the substrate molecule also changes shape slightly as it enters the active site.^[25] The active site continues to change until the substrate is completely bound, at which point the final shape and charge is determined.^[26] Image File history File links Induced_fit_diagram. ... Image File history File links Induced_fit_diagram. ... The term Side chain can have different meanings depending on the context: In chemistry and biochemistry a side chain is a part of a molecule attached to a core structure. ...

Mechanisms

Enzymes can act in several ways, all of which lower ΔG^‡:^[27]

• Lowering the activation energy by creating an environment in which the transition state is stabilized (e.g. straining the shape of a substrate - by binding the transition-state conformation of the substrate/product molecules, the enzyme distorts the bound substrate(s) into their transition state form, thereby reducing the amount of energy required to complete the transition).

• Providing an alternative pathway (e.g. temporarily reacting with the substrate to form an intermediate ES Complex which would be impossible in the absence of the enzyme).

• Reducing the reaction entropy change by bringing substrates together in the correct orientation to react. Considering ΔH^‡ alone overlooks this effect.

The sparks generated by striking steel against a flint provide the activation energy to initiate combustion in this Bunsen burner. ...

Dynamics and function

Recent investigations have provided new insights into the connection between internal dynamics of enzymes and their mechanism of catalysis.^[28][29][30] An enzyme's internal dynamics are described as the movement of internal parts (e.g. amino acids, a group of amino acids, a loop region, an alpha helix, neighboring beta-sheets or even entire domain) of these biomolecules, which can occur at various time-scales ranging from femtoseconds to seconds. Networks of protein residues throughout an enzyme's structure can contribute to catalysis through dynamic motions.^{[31][32][33][34]} Protein motions are vital to many enzymes, but whether small and fast vibrations or larger and slower conformational movements are more important depends on the type of reaction involved. These new insights also have implications in understanding allosteric effects, producing designer enzymes and developing new drugs. A femtosecond is the SI unit of time equal to 10-15 of a second. ...

Allosteric modulation

Allosteric enzymes change their structure in response to binding of effectors. Modulation can be direct, where the effector binds directly to binding sites in the enzyme, or indirect, where the effector binds to other proteins or protein subunits that interact with the allosteric enzyme and thus influence catalytic activity. In biochemistry, an enzyme or other protein is allosteric if its activity or efficiency changes in response to the binding of an effector molecule at a so-called allosteric site. ... An effector is a small molecule that binds to a protein and thereby alters the activity of that protein. ... A binding site is a region on a protein to which specific ligands bind. ... In structural biology, a protein subunit or subunit protein is a double protein molecule that assembles (or coassembles) with other protein molecules to form a multimeric or oligomeric protein. ...

Cofactors and coenzymes

Main articles: Cofactor (biochemistry) and Coenzyme

A cofactor is any substance that needs to be present in addition to an enzyme to catalyze a certain reaction. ... Coenzyme A Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. ...

Cofactors

Some enzymes do not need any additional components to show full activity. However, others require non-protein molecules to be bound for activity. Cofactors can be either inorganic (e.g., metal ions and iron-sulfur clusters) or organic compounds, (e.g., flavin and heme). Organic cofactors (coenzymes) are usually prosthetic groups, which are tightly bound to the enzymes that they assist. These tightly-bound cofactors are distinguished from other coenzymes, such as NADH, since they are not released from the active site during the reaction. Inorganic chemistry is the branch of chemistry concerned with the properties and reactions of inorganic compounds. ... An iron-sulfur cluster is a structural motif found in certain metalloproteins, such as the ferredoxins, as well as NADH dehydrogenase and Coenzyme Q - cytochrome c reductase of the electron transfer system. ... An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates, carbon oxides and gases containing carbon. ... Riboflavin Flavin is a vaginal ring whose biochemical smell is pungent. ... Structure of Heme b A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... A coenzyme is an organic non-protein molecule that is a functional part of an enzyme. ... Space-filling model of NADH Nicotinamide adenine dinucleotide (NAD+) is an important coenzymes found in cells. ...

An example of an enzyme that contains a cofactor is carbonic anhydrase, and is shown in the ribbon diagram above with a zinc cofactor bound in its active site.^[35] These tightly-bound molecules are usually found in the active site and are involved in catalysis. For example, flavin and heme cofactors are often involved in redox reactions. Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid interconversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ...

Enzymes that require a cofactor but do not have one bound are called apoenzymes. An apoenzyme together with its cofactor(s) is called a holoenzyme (i.e., the active form). Most cofactors are not covalently attached to an enzyme, but are very tightly bound. However, organic prosthetic groups can be covalently bound (e.g., thiamine pyrophosphate in the enzyme pyruvate dehydrogenase). Thiamine mononitrate Thiamine or thiamin, also known as vitamin B1, is a colorless compound with chemical formula C12H17ClN4OS. It is soluble in water and insoluble in alcohol. ... Pyruvate dehydrogenase is an enzyme (E1) in the pyruvate dehydrogenase complex (PDC). ...

Coenzymes

Space-filling model of the coenzyme NADH

Coenzymes are small molecules that transport chemical groups from one enzyme to another.^[36] Some of these chemicals such as riboflavin, thiamine and folic acid are vitamins, this is when these compounds cannot be made in the body and must be acquired from the diet. The chemical groups carried include the hydride ion (H^-) carried by NAD or NADP⁺, the acetyl group carried by coenzyme A, formyl, methenyl or methyl groups carried by folic acid and the methyl group carried by S-adenosylmethionine. Image File history File links Download high-resolution version (986x1100, 284 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Enzyme Nicotinamide adenine dinucleotide User:Benjah-bmm27/Gallery User:Ben Mills/Gallery ... Image File history File links Download high-resolution version (986x1100, 284 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Enzyme Nicotinamide adenine dinucleotide User:Benjah-bmm27/Gallery User:Ben Mills/Gallery ... Molecular graphics is the discipline and philosophy of studying molecules and their properties through graphical representation. ... Riboflavin (E101), also known as vitamin B2, is an easily absorbed micronutrient with a key role in maintaining health in animals. ... For the similarly-spelled nucleic acid, see Thymine Thiamine or thiamin, also known as vitamin B1, is one of the B vitamins. ... Folic acid and folate (the anion form) are forms of the water-soluble Vitamin B9. ... Retinol (Vitamin A) Vitamins are nutrients required in very small amounts for essential metabolic reactions in the body [1]. The term vitamin does not encompass other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids. ... A hydride is a compound of hydrogen with more electropositive elements. ... Space-filling model of NADH Nicotinamide adenine dinucleotide (NAD+) is an important coenzymes found in cells. ... Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidization of fatty acids, and the oxidation of pyruvate in the citric acid cycle. ... Folic acid and folate (the anion form) are forms of the water-soluble Vitamin B9. ... It has been suggested that this article or section be merged into S-Adenosyl methionine. ...

Since coenzymes are chemically changed as a consequence of enzyme action, it is useful to consider coenzymes to be a special class of substrates, or second substrates, which are common to many different enzymes. For example, about 700 enzymes are known to use the coenzyme NADH.^[37]

Coenzymes are usually regenerated and their concentrations maintained at a steady level inside the cell: for example, NADPH is regenerated through the pentose phosphate pathway and S-adenosylmethionine by methionine adenosyltransferase. The pentose phosphate pathways Nonoxidative phase The pentose phosphate pathway (also called Phosphogluconate Pathway, or Hexose Monophosphate Shunt [HMP shunt]) is a process that serves to generate NADPH and the synthesis of pentose (5-carbon) sugars. ...

Thermodynamics

Main articles: Activation energy, Thermodynamic equilibrium, and Chemical equilibrium

Diagram of a catalytic reaction, showing the energy niveau at each stage of the reaction. The substrates usually need a large amount of energy to reach the transition state, which then decays into the end product. The enzyme stabilizes the transition state, reducing the energy needed to form this species and thus reducing the energy required to form products.

As all catalysts, enzymes do not alter the position of the chemical equilibrium of the reaction. Usually, in the presence of an enzyme, the reaction runs in the same direction as it would without the enzyme, just more quickly. However, in the absence of the enzyme, other possible uncatalyzed, "spontaneous" reactions might lead to different products, because in those conditions this different product is formed faster. The sparks generated by striking steel against a flint provide the activation energy to initiate combustion in this Bunsen burner. ... Insert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non-formatted text hereInsert non... Chemical equilibrium is the state in which the concentrations of the reactants and products have no net change over time. ... Image File history File links Activation2_updated. ... Image File history File links Activation2_updated. ...

Furthermore, enzymes can couple two or more reactions, so that a thermodynamically favorable reaction can be used to "drive" a thermodynamically unfavorable one. For example, the hydrolysis of ATP is often used to drive other chemical reactions. Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ...

Enzymes catalyze the forward and backward reactions equally. They do not alter the equilibrium itself, but only the speed at which it is reached. For example, carbonic anhydrase catalyzes its reaction in either direction depending on the concentration of its reactants. Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid interconversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. ...

(in tissues; high CO₂ concentration)

(in lungs; low CO₂ concentration)

Nevertheless, if the equilibrium is greatly displaced in one direction, that is, in a very exergonic reaction, the reaction is effectively irreversible. Under these conditions the enzyme will, in fact, only catalyze the reaction in the thermodynamically allowed direction. Biological tissue is a collection of interconnected cells that perform a similar function within an organism. ... Human respiratory system The lungs flank the heart and great vessels in the chest cavity. ... Look up exergonic in Wiktionary, the free dictionary. ...

Kinetics

Main article: Enzyme kinetics

Mechanism for a single substrate enzyme catalyzed reaction. The enzyme (E) binds a substrate (S) and produces a product (P).

Enzyme kinetics is the investigation of how enzymes bind substrates and turn them into products. The rate data used in kinetic analyses are obtained from enzyme assays. In 1913 Leonor Michaelis and Maud Menten proposed a quantitative theory of enzyme kinetics, which is referred to as Michaelis-Menten kinetics.^[38] Their work was further developed by G. E. Briggs and J. B. S. Haldane, who derived kinetic equations that are still widely used today.^[39] It has been suggested that this article or section be merged with Enzyme. ... Image File history File links Simple_mechanism. ... Image File history File links Simple_mechanism. ... Enzyme assays are laboratory methods for measuring enzymatic activity. ... Leonor Michaelis (January 16, 1875 – October 8, 1947) was a German biochemist and physician famous for his work with Maud Menten in enzyme kinetics and Michaelis-Menten kinetics. ... Maud Leonora Menten (March 20, 1879 – July 26, 1960) was a Canadian medical scientist who made significant contributions to enzyme kinetics and histochemistry. ... Michaelis-Menten kinetics describes the kinetics of many enzymes. ... George Edward Briggs (25 June 1893 - 7 February 1985) was a British botanist. ... John Burdon Sanderson Haldane (November 5, 1892 – December 1, 1964), who normally used J.B.S. as a first name, was a British geneticist and evolutionary biologist. ...

The major contribution of Michaelis and Menten was to think of enzyme reactions in two stages. In the first, the substrate binds reversibly to the enzyme, forming the enzyme-substrate complex. This is sometimes called the Michaelis-Menten complex in their honor. The enzyme then catalyzes the chemical step in the reaction and releases the product.

Saturation curve for an enzyme reaction showing the relation between the substrate concentration (S) and rate (v).

Enzymes can catalyze up to several million reactions per second. For example, the reaction catalyzed by orotidine 5'-phosphate decarboxylase will consume half of its substrate in 78 million years if no enzyme is present. However, when the decarboxylase is added, the same process takes just 25 milliseconds.^[40] Enzyme rates depend on solution conditions and substrate concentration. Conditions that denature the protein abolish enzyme activity, such as high temperatures, extremes of pH or high salt concentrations, while raising substrate concentration tends to increase activity. To find the maximum speed of an enzymatic reaction, the substrate concentration is increased until a constant rate of product formation is seen. This is shown in the saturation curve, shown on the right. Saturation happens because, as substrate concentration increases, more and more of the free enzyme is converted into the substrate-bound ES form. At the maximum velocity (V_max) of the enzyme, all enzyme active sites are saturated with substrate, and the amount of ES complex is the same as the total amount of enzyme. Image File history File links Size of this preview: 800 × 580 pixelsFull resolution (1744 × 1264 pixel, file size: 63 KB, MIME type: image/png) Michaelis-Menten saturation curve of an enzyme reaction I, the creator of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 580 pixelsFull resolution (1744 × 1264 pixel, file size: 63 KB, MIME type: image/png) Michaelis-Menten saturation curve of an enzyme reaction I, the creator of this work, hereby release it into the public domain. ... Orotidine 5-phosphate decarboxylase is an enzyme involved in pyrimidine metabolism. ...

However, V_max is only one kinetic constant of enzymes. The amount of substrate needed to achieve a given rate of reaction is also important. This is given by the Michaelis-Menten constant (K_m), which is the substrate concentration required for an enzyme to reach one-half its maximum velocity. Each enzyme has a characteristic K_m for a given substrate, and this can show how tight the binding of the substrate is to the enzyme. Another useful constant is k_cat, which is the number of substrate molecules handled by one active site per second. Michaelis-Menten kinetics describe the rate of enzyme mediated reactions for many enzymes. ...

The efficiency of an enzyme can be expressed in terms of k_cat/K_m. This is also called the specificity constant and incorporates the rate constants for all steps in the reaction. Because the specificity constant reflects both affinity and catalytic ability, it is useful for comparing different enzymes against each other, or the same enzyme with different substrates. The theoretical maximum for the specificity constant is called the diffusion limit and is about 10⁸ to 10⁹ (M^-1 s^-1). At this point every collision of the enzyme with its substrate will result in catalysis, and the rate of product formation is not limited by the reaction rate but by the diffusion rate. Enzymes with this property are called catalytically perfect or kinetically perfect. Example of such enzymes are triose-phosphate isomerase, carbonic anhydrase, acetylcholinesterase, catalase, fumarase, ß-lactamase, and superoxide dismutase. In chemical kinetics a reaction rate constant quantifies the speed of a chemical reaction. ... Catalytically perfect enzyme or kineticall perfect enzyme is an enzyme that catalyzes so efficiently, that almost every time enzyme meets its substrate, the reaction occurs. ... Triose-phosphate isomerase (TIM), is an enzyme (EC 5. ... Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid interconversion of carbon dioxide and water into carbonic acid, protons, and bicarbonate ions. ... In biochemistry, cholinesterase is a term which refers to one of the two enzymes (EC 3. ... Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ... Structure of the monomeric unit of human superoxide dismutase 2 The enzyme superoxide dismutase (SOD, EC 1. ...

Michaelis-Menten kinetics relies on the law of mass action, which is derived from the assumptions of free diffusion and thermodynamically-driven random collision. However, many biochemical or cellular processes deviate significantly from these conditions, because of very high concentrations, phase-separation of the enzyme/substrate/product, or one or two-dimensional molecular movement.^[41] In these situations, a fractal Michaelis-Menten kinetics may be applied.^{[42][43][44][45]} Mass action in science is the idea that a large number of small units (especially atoms or molecules) acting randomly by themselves can in fact have a larger pattern. ... This article or section does not cite any references or sources. ... The boundary of the Mandelbrot set is a famous example of a fractal. ... Michaelis-Menten kinetics describes the kinetics of many enzymes. ...

Some enzymes operate with kinetics which are faster than diffusion rates, which would seem to be impossible. Several mechanisms have been invoked to explain this phenomenon. Some proteins are believed to accelerate catalysis by drawing their substrate in and pre-orienting them by using dipolar electric fields. Other models invoke a quantum-mechanical tunneling explanation, whereby a proton or an electron can tunnel through activation barriers, although for proton tunneling this model remains somewhat controversial.^[46][47] Quantum tunneling for protons has been observed in tryptamine.^[48] This suggests that enzyme catalysis may be more accurately characterized as "through the barrier" rather than the traditional model, which requires substrates to go "over" a lowered energy barrier. Quantum tunneling is the quantum-mechanical effect of transitioning through a classically-forbidden energy state. ... Tryptamine (3-(2-aminoethyl)indole) is a monoamine compound that is widespread in nature. ...

Inhibition

Competitive inhibitors bind reversibly to the enzyme, preventing the binding of substrate. On the other hand, binding of substrate prevents binding of the inhibitor. Substrate and inhibitor compete for the enzyme.

Main article: Enzyme inhibitor

Enzyme reaction rates can be decreased by various types of enzyme inhibitors. Image File history File links Competitive_inhibition. ... Image File history File links Competitive_inhibition. ... HIV protease in a complex with the protease inhibitor ritonavir. ... HIV protease in a complex with the protease inhibitor ritonavir. ...

Reversible inhibitors

Competitive inhibition

In competitive inhibition the inhibitor binds to the substrate binding site (figure right, top, thus preventing substrate from binding (EI complex). Often competitive inhibitors strongly resemble the real substrate of the enzyme. For example, methotrexate is a competitive inhibitor of the enzyme dihydrofolate reductase, which catalyzes the reduction of dihydrofolate to tetrahydrofolate. The similarity between the structures of folic acid and this drug are shown in the figure to the right bottom. Methotrexate (rINN) (IPA: ), abbreviated MTX and formerly known as amethopterin, is an antimetabolite drug used in treatment of cancer and autoimmune diseases. ... Categories: Biochemistry stubs | EC 1. ... Folic acid and folate (the anion form) are forms of the water-soluble Vitamin B9. ... Folic acid and folate (the anion form) are forms of the water-soluble Vitamin B9. ...

Non-competitive inhibition

Non-competitive inhibitors can bind either to the active site, or to other parts of the enzyme far away from the substrate-binding site. Moreover, non-competitive inhibitors bind to the enzyme-substrate (ES) complex and to the free enzyme. Their binding to this site changes the shape of the enzyme and stops the active site binding substrate(s). Consequently, since there is no direct competition between the substrate and inhibitor for the enzyme, the extent of inhibition depends only on the inhibitor concentration and will not be affected by the substrate concentration.

Irreversible inhibitors

Some enzyme inhibitors react with the enzyme and form a covalent adduct with the protein. The inactivation produced by this type of inhibitor is irreversible. A class of these compounds called suicide inhibitors includes eflornithine a drug used to treat the parasitic disease sleeping sickness.^[49] Penicillin and its derivatives also act in this manner. With these drugs, the compound is bound in the active site and the enzyme then converts the inhibitor into an activated form that reacts irreversibly with one or more with amino acid residues. Covalent bonding is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. ... Suicide inhibition, also known as suicide inactivators and mechanism-based inactivators, is a form of irreversible enzyme inhibition that occurs when an enzyme binds a substrate analogue and forms a complex with it during the normal catalysis reaction. ... Eflornithine (α-difluoromethylornithine or DFMO) is a drug manufactured by Aventis which has various uses. ... Sleeping sickness or African trypanosomiasis is a parasitic disease in people and animals, caused by protozoa of genus Trypanosoma and transmitted by the tsetse fly. ... Penicillin nucleus Penicillin (sometimes abbreviated PCN) refers to a group of β-lactam antibiotics used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms. ...

The coenzyme folic acid (left) and the anti-cancer drug methotrexate (right) are very similar in structure. As a result, methotrexate is a competitive inhibitor of many enzymes that use folates.

Image File history File links Methotrexate_and_folic_acid_compared. ... Image File history File links Methotrexate_and_folic_acid_compared. ...

Uses of inhibitors

Inhibitors are often used as drugs, but they can also act as poisons. However, the difference between a drug and a poison is usually only a matter of amount, since most drugs are toxic at some level, as Paracelsus wrote, "In all things there is a poison, and there is nothing without a poison."^[50] Equally, antibiotics and other anti-infective drugs are just specific poisons that kill a pathogen but not its host. Paracelsus (11 November or 17 December 1493 in Einsiedeln, Switzerland - 24 September 1541) was an alchemist, physician, astrologer, and general occultist. ... An antibiotic is a drug that kills or slows the growth of bacteria. ...

An example of an inhibitor being used as a drug is aspirin, which inhibits the COX-1 and COX-2 enzymes that produce the inflammation messenger prostaglandin, thus suppressing pain and inflammation. The poison cyanide is an irreversible enzyme inhibitor that combines with the copper and iron in the active site of the enzyme cytochrome c oxidase and blocks cellular respiration.^[51] Aspirin, or acetylsalicylic acid (IPA: ), (acetosal) is a drug in the family of salicylates, often used as an analgesic (to relieve minor aches and pains), antipyretic (to reduce fever), and as an anti-inflammatory. ... Cyclooxygenase (COX) is an enzyme (EC 1. ... Cyclooxygenase (COX) is an enzyme (EC 1. ... An abscess on the skin, showing the redness and swelling characteristic of inflammation. ... Chemical structure of prostaglandin E1 (PGE1). ... The cyanide ion, CN−. From the top: 1. ... Cytochrome c oxidase The enzyme cytochrome c oxidase (PDB 2OCC, EC 1. ... Cellular respiration describes the metabolic reactions and processes that take place in a cell to obtain biochemical energy from fuel molecules. ...

In many organisms inhibitors may act as part of a feedback mechanism. If an enzyme produces too much of one substance in the organism, that substance may act as an inhibitor for the enzyme that produces it, causing production of the substance to slow down or stop when there is sufficient amount. This is a form of negative feedback. It has been suggested that this article or section be merged with Feedback loop. ... This article or section does not cite any references or sources. ...

Biological function

Enzymes serve a wide variety of functions inside living organisms. They are indispensable for signal transduction and cell regulation, often via kinases and phosphatases.^[52] They also generate movement, with myosin hydrolysing ATP to generate muscle contraction and also moving cargo around the cell as part of the cytoskeleton.^[53] Other ATPases in the cell membrane are ion pumps involved in active transport. Enzymes are also involved in more exotic functions, such as luciferase generating light in fireflies.^[54] Viruses can also contain enzymes for infecting cells, such as the HIV integrase and reverse transcriptase, or for viral release from cells, like the influenza virus neuraminidase. Overview of signal transduction pathways In biology, signal transduction refers to any process by which a cell converts one kind of signal or stimulus into another, most often involving ordered sequences of biochemical reactions inside the cell, that are carried out by enzymes and linked through second messengers resulting in... In biochemistry, a kinase is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules (substrates); the process is termed phosphorylation. ... A phosphatase is an enzyme that hydrolyses phosphoric acid monoesters into a phosphate ion and a molecule with a free hydroxyl group. ... Myosin is a motor protein filament found in muscle tissue. ... A top-down view of skeletal muscle A muscle contraction (also known as a muscle twitch or simply twitch) occurs when a muscle cell (called a muscle fiber) lengthens or shortens. ... The eukaryotic cytoskeleton. ... In biology, an ion pump is a transmembrane protein that moves ions across a plasma membrane against their concentration gradient. ... Sodium-Potassium pump, an example of Primary active transport secondary active transport Active transport (sometimes called active uptake) is the mediated transport of biochemicals, and other atomic/molecular substances, across membranes. ... Luciferase is a generic name for enzymes commonly used in nature for bioluminescence. ... Genera Curtos Cyphonocerus Drilaster Ellychnia Hotaria Lampyris Lucidina Lucidota Luciola - Japanese fireflies Phausis Photinus - common eastern firefly Photuris Pristolycus Pyractomena Pyrocoelia Stenocladius many others Wikispecies has information related to: Lampyridae Lampyridae is a family in the beetle order Coleoptera, members of which are commonly called fireflies, lightning bugs, or glow... Groups I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+)ssRNA viruses V: (-)ssRNA viruses VI: ssRNA-RT viruses VII: dsDNA-RT viruses A virus (from the Latin noun virus, meaning toxin or poison) is a microscopic particle (ranging in size from 20 - 300 nm) that can infect the... Integrase is an enzyme produced by a retrovirus (including HIV) that enables its genetic material to be integrated into the DNA of the infected cell. ... In biochemistry, a reverse transcriptase, also known as RNA-dependent DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA. Normal transcription involves the synthesis of RNA from DNA, hence reverse transcription is the reverse of this. ... Influenza, commonly known as flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). ... Neuraminidase is a glycoside hydrolase enzyme (EC 3. ...

An important function of enzymes is in the digestive systems of animals. Enzymes such as amylases and proteases break down large molecules (starch or proteins, respectively) into smaller ones, so they can be absorbed by the intestines. Starch is inabsorbable in the intestine but enzymes hydrolyse the starch chains into smaller molecules such as maltose and eventually glucose, which can then be absorbed. Different enzymes digest different food substances. In ruminants which have a herbivorous diets, bacteria in the gut produce another enzyme, cellulase to break down the cellulose cell walls of plant fiber. The gastrointestinal tract or digestive tract, also referred to as the GI tract or the alimentary canal, (nourishment canal) or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and expels the remaining waste. ... Amylase is the name given to glycoside hydrolase enzymes that break down starch. ... Peptidases (proteases [pronounced pro-tea-aces] and proteolytic enzymes are also commonly used) are enzymes which break peptide bonds of proteins. ... Starch (CAS# 9005-25-8) is a complex carbohydrate which is insoluble in water; it is used by plants as a way to store excess glucose. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... α-Maltose Maltose (also: malt sugar, di-glucose) is a disaccharide with the molecular formula C12H22O11. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... A ruminant is any hooved animal that digests its food in two steps, first by eating the raw material and regurgitating a semi-digested form known as cud, then eating the cud. ... In zoology, an herbivore is an animal that is adapted to eat primarily plants (rather than meat). ... Cellulase is an enzyme complex which breaks down cellulose to beta-glucose. ...

Several enzymes can work together in a specific order, creating metabolic pathways. In a metabolic pathway, one enzyme takes the product of another enzyme as a substrate. After the catalytic reaction, the product is then passed on to another enzyme. Sometimes more than one enzyme can catalyse the same reaction in parallel, this can allow more complex regulation: with for example a low constant activity being provided by one enzyme but an inducible high activity from a second enzyme. In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell, catalyzed by enzymes, resulting in either the formation of a metabolic product to be used or stored by the cell, or the initiation of another metabolic pathway (then called a flux generating step). ...

Enzymes determine what steps occur in these pathways. Without enzymes, metabolism would neither progress through the same steps, nor be fast enough to serve the needs of the cell. Indeed, a metabolic pathway such as glycolysis could not exist independently of enzymes. Glucose, for example, can react directly with ATP to become phosphorylated at one or more of its carbons. In the absence of enzymes, this occurs so slowly as to be insignificant. However, if hexokinase is added, these slow reactions continue to take place except that phosphorylation at carbon 6 occurs so rapidly that if the mixture is tested a short time later, glucose-6-phosphate is found to be the only significant product. Consequently, the network of metabolic pathways within each cell depends on the set of functional enzymes that are present. Glycolysis is a metabolic pathway by which a 6-carbon glucose (Glc) molecule is oxidized to two molecules of pyruvic acid (Pyr). ... A phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein or a small molecule or the introduction of a phosphate group into an organic molecule. ... A hexokinase is an enzyme that phosphorylates a six-carbon sugar, a hexose, to a hexose phosphate. ... Glucose 6-phosphate is glucose sugar phosphorylated on carbon 6. ...

Control of activity

There are five main ways that enzyme activity is controlled in the cell.

1. Enzyme production (transcription and translation of enzyme genes) can be enhanced or diminished by a cell in response to changes in the cell's environment. This form of gene regulation is called enzyme induction and inhibition. For example, bacteria may become resistant to antibiotics such as penicillin because enzymes called beta-lactamases are induced that hydrolyse the crucial beta-lactam ring within the penicillin molecule. Another example are enzymes in the liver called cytochrome P450 oxidases, which are important in drug metabolism. Induction or inhibition of these enzymes can cause drug interactions.
2. Enzymes can be compartmentalized, with different metabolic pathways occurring in different cellular compartments. For example, fatty acids are synthesized by one set of enzymes in the cytosol, endoplasmic reticulum and the Golgi apparatus and used by a different set of enzymes as a source of energy in the mitochondrion, through β-oxidation.^[55]
3. Enzymes can be regulated by inhibitors and activators. For example, the end product(s) of a metabolic pathway are often inhibitors for one of the first enzymes of the pathway (usually the first irreversible step, called committed step), thus regulating the amount of end product made by the pathways. Such a regulatory mechanism is called a negative feedback mechanism, because the amount of the end product produced is regulated by its own concentration. Negative feedback mechanism can effectively adjust the rate of synthesis of intermediate metabolites according to the demands of the cells. This helps allocate materials and energy economically, and prevents the manufacture of excess end products. Like other homeostatic devices, the control of enzymatic action helps to maintain a stable internal environment in living organisms.
4. Enzymes can be regulated through post-translational modification. This can include phosphorylation, myristoylation and glycosylation. For example, in the response to insulin, the phosphorylation of multiple enzymes, including glycogen synthase, helps control the synthesis or degradation of glycogen and allows the cell to respond to changes in blood sugar.^[56] Another example of post-translational modification is the cleavage of the polypeptide chain. Chymotrypsin, a digestive protease, is produced in inactive form as chymotrypsinogen in the pancreas and transported in this form to the stomach where it is activated. This stops the enzyme from digesting the pancreas or other tissues before it enters the gut. This type of inactive precursor to an enzyme is known as a zymogen.
5. Some enzymes may become activated when localized to a different environment (eg. from a reducing (cytoplasm) to an oxidising (periplasm) environment, high pH to low pH etc). For example, hemagglutinin of the influenza virus undergoes a conformational change once it encounters the acidic environment of the host cell vesicle causing its activation.^[57]

A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... Gene modulation redirects here. ... Enzyme induction is a process in which a molecule ( a drug) induces ( initiates or enhances) the expression of an enzyme. ... Antibiotic resistance is the ability of a micro-organism to withstand the effects of an antibiotic. ... Penicillin nucleus Penicillin (sometimes abbreviated PCN) refers to a group of β-lactam antibiotics used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms. ... Beta-lactamase is a type of enzyme (EC 3. ... A beta-lactam (β-lactam) or penam is a lactam with a heteroatomic ring structure, consisting of three carbon atoms and one nitrogen atom. ... The liver is an organ present in vertebrates and some other animals. ... Cytochrome P450 Oxidase (CYP2E1) Cytochrome P450 oxidase (commonly abbreviated CYP) is a generic term for a large number of related, but distinct, oxidative enzymes (EC 1. ... Drug metabolism is the metabolism of drugs, their biochemical modification or degradation, usually through specialized enzymatic systems. ... A drug interaction is a situation in which a substance affects the activity of a drug, i. ... Cellular compartments in cell biology comprise all closed parts within a cell whose lumen is usually surrounded by a single or double lipid layer membrane. ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid (or organic acid), often with a long aliphatic tail (long chains), either saturated or unsaturated. ... The cytosol (cf. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Diagram of the endomembrane system in a typical eukaryote cell Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) (from Greek μιτος or mitos, thread + χονδριον or khondrion, granule) is a membrane-enclosed organelle, found in most eukaryotic cells. ... Beta oxidation is the process by which fats, in the form of Acyl-CoA molecules, are broken down in the mitochondria to generate Acetyl-CoA, the entry molecule for the Krebs Cycle. ... HIV protease in a complex with the protease inhibitor ritonavir. ... This article or section does not cite any references or sources. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Posttranslational modification means the chemical modification of a protein after its translation. ... A phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein or a small molecule or the introduction of a phosphate group into an organic molecule. ... Myristic acid, also called Tetradecanoic acid, is a common saturated fatty acid found in dairy products. ... Glycosylation is the process or result of addition of saccharides to proteins and lipids. ... Insulin (from Latin insula, island, as it is produced in the Islets of Langerhans in the pancreas) is a polypeptide hormone that regulates carbohydrate metabolism. ... A phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein or a small molecule or the introduction of a phosphate group into an organic molecule. ... Glycogen synthase (UDP-glucose-glycogen glucosyltransferase) is a glycosyltransferase enzyme (EC number 2. ... Electron micrograph of a section of a liver cell showing glycogen deposits as accumulations of electron dense particles (arrows). ... In medicine, blood sugar is a term used to refer to levels of glucose in the blood. ... Chymotrypsin (bovine γ chymotrypsin: PDB 1AB9, EC 3. ... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... Chymotrypsinogen is a precursor of the digestive enzyme chymotrypsin (zymogen). ... The pancreas is an organ in the digestive and endocrine system (of vertebrates[2]). It is both exocrine (secreting pancreatic juice containing digestive enzymes) and endocrine (producing several important hormones, including insulin, glucagon, and somatostatin). ... In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. ... A zymogen or a proenzyme, is an inactive enzyme precursor. ... It has been suggested that Cytoplast be merged into this article or section. ... The periplasmic space is the space seen between the plasma membrane and the outer membrane in the gram-negative bacteria. ... Hemagglutinin, as depicted in a simplified molecular model. ... Influenza, commonly known as flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). ... This article or section is in need of attention from an expert on the subject. ...

Involvement in disease

Phenylalanine hydroxylase. Created from PDB 1KW0

Since the tight control of enzyme activity is essential for homeostasis, any malfunction (mutation, overproduction, underproduction or deletion) of a single critical enzyme can lead to a genetic disease. The importance of enzymes is shown by the fact that a lethal illness can be caused by the malfunction of just one type of enzyme out of the thousands of types present in our bodies. Image File history File links Download high-resolution version (678x713, 246 KB) Summary I am author Licensing I, the creator of this work, hereby release it into the public domain. ... Image File history File links Download high-resolution version (678x713, 246 KB) Summary I am author Licensing I, the creator of this work, hereby release it into the public domain. ... Categories: Biochemistry stubs | EC 1. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... A genetic disorder, or genetic disease is a disease caused, at least in part, by the genes of the person with the disease. ...

One example is the most common type of phenylketonuria. A mutation of a single amino acid in the enzyme phenylalanine hydroxylase, which catalyzes the first step in the degradation of phenylalanine, results in build-up of phenylalanine and related products. This can lead to mental retardation if the disease is untreated.^[58] Phenylketonuria (PKU; ) is a human genetic disorder in which the body does not contain the enzyme phenylalanine hydroxylase, necessary to metabolize phenylalanine to tyrosine, and converts phenylalanine instead to phenylpyruvic acid. ... Categories: Biochemistry stubs | EC 1. ... Phe redirects here. ... Mental retardation is a term for a pattern of persistently slow learning of basic motor and language skills (milestones) during childhood, and a significantly below-normal global intellectual capacity as an adult. ...

Another example is when germline mutations in genes coding for DNA repair enzymes cause hereditary cancer syndromes such as xeroderma pigmentosum. Defects in these enzymes cause cancer since the body is less able to repair mutations in the genome. This causes a slow accumulation of mutations and results in the development of many types of cancer in the sufferer. A Germline Mutation is any detectable, heritable variation in the lineage of germ cells. ... DNA damage resulting in multiple broken chromosomes DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. ... This article or section does not cite any references or sources. ...

Naming conventions

An enzyme's name is often derived from its substrate or the chemical reaction it catalyzes, with the word ending in -ase. Examples are lactase, alcohol dehydrogenase and DNA polymerase. This may result in different enzymes, called isoenzymes, with the same function having the same basic name. Isoenzymes have a different amino acid sequence and might be distinguished by their optimal pH, kinetic properties or immunologically. Furthermore, the normal physiological reaction an enzyme catalyzes may not be the same as under artificial conditions. This can result in the same enzyme being identified with two different names. E.g. Glucose isomerase, used industrially to convert glucose into the sweetener fructose, is a xylose isomerase in vivo. Lactase is a member of the β-galactosidase family of enzyme: enzymes that hydrolysis β 1,4 bonded attachments off of galactose. ... Alcohol Dehydrogenase Alcohol dehydrogenases are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones. ... 3D structure of the DNA-binding helix-hairpin-helix motifs in human DNA polymerase beta A DNA polymerase is an enzyme that assists in DNA replication. ... The correct title of this article is . ... Glucose Isomerase is an enzyme (EC 5. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... Fructose (or levulose) is a simple sugar (monosaccharide) found in many foods and is one of the three most important blood sugars along with glucose and galactose. ...

The International Union of Biochemistry and Molecular Biology have developed a nomenclature for enzymes, the EC numbers; each enzyme is described by a sequence of four numbers preceded by "EC". The first number broadly classifies the enzyme based on its mechanism: Italic text ... The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ...

The top-level classification is

• EC 1 Oxidoreductases: catalyze oxidation/reduction reactions
• EC 2 Transferases: transfer a functional group (e.g. a methyl or phosphate group)
• EC 3 Hydrolases: catalyze the hydrolysis of various bonds
• EC 4 Lyases: cleave various bonds by means other than hydrolysis and oxidation
• EC 5 Isomerases: catalyze isomerization changes within a single molecule
• EC 6 Ligases: join two molecules with covalent bonds

The complete nomenclature can be browsed at http://www.chem.qmul.ac.uk/iubmb/enzyme/. In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule (the oxidant, also called the hydrogen donor or electron donor) to another (the reductant, also called the hydrogen acceptor or electron acceptor). ... The most fundamental reactions in chemistry are the redox processes. ... In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group (e. ... In organic chemistry, functional groups are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... In biochemistry, a hydrolase is an enzyme that can break a chemical bond by hydrolysis. ... Hydrolysis is a chemical reaction or process in which a chemical compound reacts with water. ... In biochemistry, a lyase is an enzyme that breaks various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure. ... In biochemistry, an isomerase is any enzyme that catalyses the interconversion of isomers. ... In chemistry, isomers are molecules with the same chemical formula and often with the same kinds of chemical bonds between atoms, but in which the atoms are arranged differently (analogous to a chemical anagram). ... In biochemistry, a ligase (from the Latin verb ligāre — to bind or to glue together) is an enzyme that can catalyse the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group pendant to one of the larger molecules. ... Covalent bonding is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. ...

Industrial applications

Enzymes are used in the chemical industry and other industrial applications when extremely specific catalysts are required. However, enzymes in general are limited in the number of reactions they have evolved to catalyse and also by their lack of stability in organic solvents and at high temperatures. Consequently, protein engineering is an active area of research and involves attempts to create new enzymes with novel properties, either through rational design or in vitro evolution.^[59][60] Chemical tanks in Lillebonne, France Chemical industry includes those industries involved in the production of petrochemicals, agrochemicals, pharmaceuticals, polymers, paints, oleochemicals etc. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... Protein engineering is the application of science, mathematics, and economics to the process of developing useful or valuable proteins. ...

Application	Enzymes used	Uses
Baking industry alpha-amylase catalyzes the release of sugar monomers from starch	Fungal alpha-amylase enzymes are normally inactivated at about 50 degrees Celsius, but are destroyed during the baking process.	Catalyze breakdown of starch in the flour to sugar. Yeast action on sugar produces carbon dioxide. Used in production of white bread, buns, and rolls.
	Proteases	Biscuit manufacturers use them to lower the protein level of flour.
Baby foods	Trypsin	To predigest baby foods.
Brewing industry Germinating barley used for malt.	Enzymes from barley are released during the mashing stage of beer production.	They degrade starch and proteins to produce simple sugar, amino acids and peptides that are used by yeast for fermentation.
	Industrially produced barley enzymes	Widely used in the brewing process to substitute for the natural enzymes found in barley.
	Amylase, glucanases, proteases	Split polysaccharides and proteins in the malt.
	Betaglucosidase	Improve the filtration characteristics.
	Amyloglucosidase	Low-calorie beer.
	Proteases	Remove cloudiness produced during storage of beers.
Fruit juices	Cellulases, pectinases	Clarify fruit juices
Dairy industry Roquefort cheese	Rennin, derived from the stomachs of young ruminant animals (like calves and lambs).	Manufacture of cheese, used to hydrolyze protein.
	Microbially produced enzyme	Now finding increasing use in the dairy industry.
	Lipases	Is implemented during the production of Roquefort cheese to enhance the ripening of the blue-mould cheese.
	Lactases	Break down lactose to glucose and galactose.
Meat tenderizers	Papain	To soften meat for cooking.
Starch industry Glucose Fructose	Amylases, amyloglucosideases and glucoamylases	Converts starch into glucose and various syrups.
	Glucose isomerase	Converts glucose into fructose in production of high fructose syrups from starchy materials. These syrups have enhanced sweetening properties and lower calorific values than sucrose for the same level of sweetness.
Paper industry A paper mill in South Carolina.	Amylases, Xylanases, Cellulases and ligninases	Degrade starch to lower viscosity, aiding sizing and coating paper. Xylanases reduce bleach required for decolorising; cellulases smooth fibers, enhance water drainage, and promote ink removal; lipases reduce pitch and lignin-degrading enzymes remove lignin to soften paper.
Biofuel industry Cellulose in 3D	Cellulases	Used to break down cellulose into sugars that can be fermented (see cellulosic ethanol).
	Ligninases	Use of lignin waste
Biological detergent Laundry soap	Primarily proteases, produced in an extracellular form from bacteria	Used for presoak conditions and direct liquid applications helping with removal of protein stains from clothes.
	Amylases	Detergents for machine dish washing to remove resistant starch residues.
	Lipases	Used to assist in the removal of fatty and oily stains.
	Cellulases	Used in biological fabric conditioners.
Contact lens cleaners	Proteases	To remove proteins on contact lens to prevent infections.
Rubber industry	Catalase	To generate oxygen from peroxide to convert latex into foam rubber.
Photographic industry	Protease (ficin)	Dissolve gelatin off scrap film, allowing recovery of its silver content.
Molecular biology Part of the DNA double helix.	Restriction enzymes, DNA ligase and polymerases	Used to manipulate DNA in genetic engineering, important in pharmacology, agriculture and medicine. Essential for restriction digestion and the polymerase chain reaction. Molecular biology is also important in forensic science.

Wikibooks Cookbook has an article on Baking Baking is the technique of prolonged cooking of food by dry heat acting by conduction, and not by radiation, normally in an oven, but also in hot ashes, or on hot stones. ... Image File history File links Amylose. ... Image File history File links Amylose. ... For the fictional character, see Fungus the Bogeyman. ... {{globalize/USA} For other uses, see Flour (disambiguation). ... Baby food is any food that is made specifically for infants, roughly between the ages of six months to two years. ... Trypsin (EC 3. ... A 16th century brewer A 21st century brewer This article concerns the production of alcoholic beverages. ... Subject Malted (germinated) barley for Single Malt Scotch in the malting room at the Laphroaig distillery on Islay in Scotland. ... Subject Malted (germinated) barley for Single Malt Scotch in the malting room at the Laphroaig distillery on Islay in Scotland. ... Binomial name Hordeum vulgare L. Barley (Hordeum vulgare) is a cereal grain, which serves as a major animal feed crop, with smaller amounts used for malting and in health food. ... Malted barley Malting is a process applied to cereal grains, in which the grains are made to germinate and then are quickly dried before the plant develops. ... Beer in the glass Schlenkerla Rauchbier direct from the cask Beer is the worlds oldest[1] and most popular[2] alcoholic beverage. ... Orange juice Juice is a liquid naturally contained in vegetable or fruit tissue. ... A dairy farm near Oxford, New York in the United States. ... Image File history File links Download high resolution version (1003x800, 106 KB) Roquefort, a type of Protected Designation of Origin cheese made in France. ... Image File history File links Download high resolution version (1003x800, 106 KB) Roquefort, a type of Protected Designation of Origin cheese made in France. ... Rennet, also called rennin or chymosin (EC 3. ... This article does not adequately cite its references or sources. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ... A computer-generated image of a type of pancreatic lipase (PLRP2) from the guinea pig. ... Roquefort is a flavorful ewes-milk blue cheese from the south of France, and one of the most famous of all French cheeses. ... Country of origin  Denmark Region, town Source of milk Cows Pasteurised Texture semi-soft Aging time 8-12 weeks Certification Danish Blue cheese, also known as Danablu if it is made in Denmark, is a light, blue-veined cheese. ... Lactose is a disaccharide that consists of β-D-galactose and β-D-glucose molecules bonded through a β1-4 glycosidic linkage. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... In cooking, tenderizing is a process to break down collagens in meat to make it more palatable for consumption. ... Papain is a protease enzyme (EC 3. ... Starch (CAS# 9005-25-8) is a complex carbohydrate which is insoluble in water; it is used by plants as a way to store excess glucose. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Starch (CAS# 9005-25-8) is a complex carbohydrate which is insoluble in water; it is used by plants as a way to store excess glucose. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... Inverted sugar syrup is sucrose-based syrup treated with the glycoside hydrolase enzyme invertase, and/or an acid, which splits each sucrose molecule into one glucose and one fructose molecule. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... Fructose (or levulose) is a simple sugar (monosaccharide) found in many foods and is one of the three most important blood sugars along with glucose and galactose. ... Corn syrup, known as glucose syrup outside the United States, is a syrup made from corn starch and composed mainly of glucose. ... A calorie is a unit of measurement for energy. ... A blank sheet of paper Paper is a commodity of thin material produced by the amalgamation of fibers, typically vegetable fibers composed of cellulose, which are subsequently held together by hydrogen bonding. ... International Paper Company, on the Sampit River, Georgetown, SC Image taken by me, released under GFDL Pollinator File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... International Paper Company, on the Sampit River, Georgetown, SC Image taken by me, released under GFDL Pollinator File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Official language(s) English Capital Charleston(1670-1789) Columbia(1790-present) Largest city Columbia Largest metro area Columbia Area  Ranked 40th  - Total 34,726 sq mi (82,965 km²)  - Width 200 miles (320 km)  - Length 260 miles (420 km)  - % water 6  - Latitude 32°430N to 35°12N... Amylase is the name given to glycoside hydrolase enzymes that break down starch into glucose molecules. ... xylanase is an enzyme which Breaks down hemicellulose (xylans), a major component of the plant cell wall. ... Cellulase is an enzyme complex which breaks down cellulose to beta-glucose. ... Lignin (sometimes lignen) is a chemical compound that is most commonly derived from wood and is an integral part of the cell walls of plants, especially in tracheids, xylem fibres and sclereids. ... Viscosity is a measure of the resistance of a fluid to deform under shear stress. ... This article or section does not cite any references or sources. ... Lignin (sometimes lignen) is a chemical compound that is most commonly derived from wood and is an integral part of the cell walls of plants, especially in tracheids, xylem fibres and sclereids. ... For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, and Straight vegetable oil Sugar cane can be used as a biofuel. ... Image File history File links Download high-resolution version (1000x570, 211 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Cellulose ... Image File history File links Download high-resolution version (1000x570, 211 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Cellulose ... Cellulase is an enzyme complex which breaks down cellulose to beta-glucose. ... Cellulosic ethanol or cellanol is ethanol fuel produced from cellulose, a naturally occuring complex carbohydrate polymer commonly found in plant cell walls. ... Lignin (sometimes lignen) is a chemical compound (complex, highly cross-linked aromatic polymer) that is most commonly derived from wood and is an integral part of the cell walls of plants, especially in tracheids, xylem fibres and sclereids. ... Lignin (sometimes lignen) is a chemical compound that is most commonly derived from wood and is an integral part of the cell walls of plants, especially in tracheids, xylem fibres and sclereids. ... Laundry detergents are just one of many possible uses for detergents Detergent is a compound, or a mixture of compounds, intended to assist cleaning. ... Image File history File links Download high resolution version (2048x1536, 748 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (2048x1536, 748 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... In cell biology, molecular biology and related fields, the word extracellular means outside the cell. It is used in contrast to intracellular (inside the cell). ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Amylase is the name given to glycoside hydrolase enzymes that break down starch into glucose molecules. ... A computer-generated image of a type of pancreatic lipase (PLRP2) from the guinea pig. ... Cellulase is an enzyme complex which breaks down cellulose to beta-glucose. ... A conditioner is something which improves the quality of another material. ... A pair of contact lenses, positioned with the concave side facing upward. ... Peptidases (proteases [pronounced pro-tea-aces] and proteolytic enzymes are also commonly used) are enzymes which break peptide bonds of proteins. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... A pair of contact lenses, positioned with the concave side facing upward. ... Latex being collected from a tapped rubber tree Rubber is an elastic hydrocarbon polymer which occurs as a milky colloidal suspension (known as latex) in the sap of several varieties of plants. ... Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... A peroxide is a compound containing an oxygen-oxygen single bond. ... The LaTeX logo, typeset with LaTeX LATEX, written as LaTeX in plain text, is a document markup language and document preparation system for the TeX typesetting program. ... Photography [fÓ™tÉ‘grÓ™fi:],[foÊŠtÉ‘grÓ™fi:] is the process of recording pictures by means of capturing light on a light-sensitive medium, such as a film or sensor. ... Gelatin (also gelatine, from French gélatine) is a translucent brittle solid substance, colorless or slightly yellow, nearly tasteless and odorless. ... This article or section does not cite its references or sources. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Standard atomic weight 107. ... Molecular biology is the study of biology at a molecular level. ... Image File history File links DNA123_rotated. ... Image File history File links DNA123_rotated. ... The Double-Helix are an alien race in the Wing Commander science fiction series. ... A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the sugar-phosphate backbones (i. ... It has been suggested that sticky end/blunt end be merged into this article or section. ... Categories: Biochemistry stubs | EC 2. ... An iconic image of genetic engineering; this autoluminograph from 1986 of a glowing transgenic tobacco plant bearing the luciferase gene, illustrating the possibilities of genetic engineering. ... Pharmacology (in Greek: pharmakos (φάρμακον) meaning drug, and logos (λόγος) meaning science) is the study of how substances interact with living organisms to produce a change in function. ... medicines, see medication and pharmacology. ... A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double-stranded DNA. The enzyme makes two incisions, one through each of the sugar-phosphate backbones (i. ... PCR tubes in a stand after a colony PCR The polymerase chain reaction (PCR) is a biochemistry and molecular biology technique[1] for exponentially amplifying DNA, via enzymatic replication, without using a living organism (such as E. coli or yeast). ... Crime Scene, done by the United States Army Criminal Investigation Command Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ...

See also

• Enzyme kinetics
• Enzyme inhibitor
• Enzyme assay
• Enzyme catalysis
• SUMO enzymes
• K_i Database
• Proteonomics and protein engineering

It has been suggested that this article or section be merged with Enzyme. ... HIV protease in a complex with the protease inhibitor ritonavir. ... Enzyme assays are laboratory methods for measuring enzymatic activity. ... Enzyme catalysis is the catalysis of chemical reactions by enzyme molecules. ... SUMO enzymatic cascade, designed and donated by Abgent. ... The Ki Database (or Ki DB) is a public domain database of published binding affinities (Ki) of drugs and chemical compounds for receptors, neurotransmitter transporters, ion channels, and enzymes. ... This article or section is in need of attention from an expert on the subject. ... Protein engineering is the application of science, mathematics, and economics to the process of developing useful or valuable proteins. ...

References

René Antoine Ferchault de Réaumur. ... For the Manfred Mann album, see 2006 (album). ... October 11 is the 284th day of the year (285th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

Further reading

External links

Wikimedia Commons has media related to:

Enzymes

Food Portal

• Structure/Function of Enzymes, Web tutorial on enzyme structure and function.
• Enzyme spotlight Monthly feature at the European Bioinformatics Institute on a selected enzyme.
• UK biotech and pharmaceutical industry The Biosystems Informatics Institute (Bii) is a new UK government initiative funded by the Department of Trade and Industry and the Regional Development Agency, One NorthEast. From its outset the Institute will undertake industry-facing research and development in collaboration with the UK biotech and pharmaceutical industry.
• AMFEP, Association of Manufacturers and Formulators of Enzyme Products
• BRENDA database, a comprehensive compilation of information and literature references about all known enzymes; requires payment by commercial users.
• Enzyme Structures Database links to the known 3-D structure data of enzymes in the Protein Data Bank.
• ExPASy enzyme database, links to Swiss-Prot sequence data, entries in other databases and to related literature searches.
• KEGG: Kyoto Encyclopedia of Genes and Genomes Graphical and hypertext-based information on biochemical pathways and enzymes.
• MACiE database of enzyme reaction mechanisms.
• MetaCyc database of enzymes and metabolic pathways
• 'Face-to-Face Interview with Sir John Cornforth who was awarded a Nobel Prize for work on stereochemistry of enzyme-catalyzed reactions Freeview video by the Vega Science Trust