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Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. Metabolism is the complete set of chemical reactions that occur in living cells. These processes are the basis of life, allowing cells to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism yields energy, an example being the breakdown of food in cellular respiration. Anabolism, on the other hand, uses this energy to construct components of cells such as proteins and nucleic acids. Image File history File links Download high resolution version (1534x1100, 453 KB) File links The following pages link to this file: Adenosine triphosphate User:Benjah-bmm27/Gallery ... Image File history File links Download high resolution version (1534x1100, 453 KB) File links The following pages link to this file: Adenosine triphosphate User:Benjah-bmm27/Gallery ... Coenzyme A Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. ... Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... For other uses, see Chemical reaction (disambiguation). ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... For other uses, see Life (disambiguation). ... Anabolism is the aspect of metabolism that contributes to growth. ... Cellular respiration was discovered by mad scientist Mr. ... Anabolism is the metabolic process that builds larger molecules from smaller ones. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Look up nucleic acid in Wiktionary, the free dictionary. ... The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed into another by a sequence of enzymes. Enzymes are crucial to metabolism because they allow cells to drive desirable but thermodynamically unfavorable reactions by coupling them to favorable ones. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells. In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... This article is about the study of energy transformation in Biology and related subjects. ... In physics, two systems are coupled if they are interacting with each other. ... Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. ... The metabolism of an organism determines which substances it will find nutritious and which it will find poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals.[1] The speed of metabolism, the metabolic rate, also influences how much food an organism will require. The updated USDA food pyramid, published in 2005, is a general nutrition guide for recommended food consumption for humans. ... The skull and crossbones symbol (Jolly Roger) traditionally used to label a poisonous substance. ... Prokaryotic bacteria cell structure Prokaryotes (IPA: //) are a group of organisms that lack a cell nucleus (= karyon), or any other membrane-bound organelles. ... Hydrogen sulfide (hydrogen sulphide in British English) is the chemical compound with the formula H2S. This colorless, toxic and flammable gas is responsible for the foul odor of rotten eggs and flatulence. ... A striking feature of metabolism is the similarity of the basic metabolic pathways between even vastly different species. For example, the set of chemical intermediates in the citric acid cycle are found universally, among living cells as diverse as the unicellular bacteria Escherichia coli and huge multicellular organisms like elephants.[2] This shared metabolic structure is most likely the result of the high efficiency of these pathways, and of their early appearance in evolutionary history.[3][4] Overview of the citric acid cycle The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle, after Hans Adolf Krebs who identified the cycle) is a series of chemical reactions of central importance in all living cells that use oxygen as part... A cluster of Escherichia coli bacteria magnified 10,000 times. ... 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. ... E. coli redirects here. ... Wild-type Caenorhabditis elegans hermaphrodite stained to highlight the nuclei of all cells Multicellular organisms are organisms consisting of more than one cell, and having differentiated cells that perform specialized functions. ... Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Elephas antiquus † Elephas beyeri † Elephas celebensis † Elephas cypriotes † Elephas ekorensis † Elephas falconeri † Elephas iolensis † Elephas planifrons † Elephas platycephalus † Elephas recki † Stegodon † Mammuthus † Elephantidae (the elephants) is a family of pachyderm, and the only remaining family in the order Proboscidea... Contents 1 Key biochemicals 1.1 Amino acids and proteins 1.2 Lipids 1.3 Carbohydrates 1.4 Nucleotides 1.5 Coenzymes 1.6 Minerals and cofactors 2 Catabolism 2.1 Digestion 2.2 Energy from organic compounds 2.3 Oxidative phosphorylation 2.4 Energy from inorganic compounds 2.5 Energy from light 3 Anabolism 3.1 Carbon fixation 3.2 Carbohydrates and glycans 3.3 Fatty acids, isoprenoids and steroids 3.4 Proteins 3.5 Nucleotide synthesis and salvage 4 Xenobiotics and redox metabolism 5 Thermodynamics of living organisms 6 Regulation and control 7 Evolution 8 Investigation and manipulation 9 History 10 See also 11 References 12 Further reading 13 External links [edit] Key biochemicals Further information: Biomolecule, cell (biology) and biochemistry Structure of a triacylglycerol lipid. Most of the structures that make up animals, plants and microbes are made from three basic classes of molecule: amino acids, carbohydrates and lipids (often called fats). As these molecules are vital for life, metabolism focuses on making these molecules, in the construction of cells and tissues, or breaking them down and using them as a source of energy, in the digestion and use of food. Many important biochemicals can be joined together to make polymers such as DNA and proteins. These macromolecules are essential parts of all living organisms. Some of the most common biological polymers are listed in the table below. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Biochemistry is the study of the chemical processes in living organisms. ... Image File history File links Download high-resolution version (1100x893, 274 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fat Trimyristin User:Benjah-bmm27/Gallery User:Ben Mills/Gallery ... Image File history File links Download high-resolution version (1100x893, 274 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fat Trimyristin User:Benjah-bmm27/Gallery User:Ben Mills/Gallery ... This article is about lipid molecules, for FAT see File Allocation Table. ... Phenylalanine is one of the standard amino acids. ... Lactose is a disaccharide found in milk. ... Some common lipids. ... For other uses, see FAT. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ... A polymer (from Greek: πολυ, polu, many; and μέρος, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... A macromolecule is a molecule composed of a very large number of atoms. ... Type of molecule Name of monomer forms Name of polymer forms Examples of polymer forms Amino acids Amino acids Proteins (also called polypeptides) Fibrous proteins and globular proteins Carbohydrates Monosaccharides Polysaccharides Starch, glycogen and cellulose Nucleic acids Nucleotides Polynucleotides DNA and RNA 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. ... A polymer (from Greek: πολυ, polu, many; and μέρος, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ... Phenylalanine is one of the standard amino acids. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Fibrous proteins, also called scleroproteins, are long filamentous protein molecules that form one of the two main classes of tertiary structure protein (the other being globular proteins). ... 3-dimensional structure of hemoglobin, a globular protein. ... Lactose is a disaccharide found in milk. ... Monosaccharides are the simplest form of carbohydrates. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... Starch (CAS# 9005-25-8, chemical formula (C6H10O5)n,[1]) is a mixture of amylose and amylopectin (usually in 20:80 or 30:70 ratios). ... This article does not cite any references or sources. ... Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a polysaccharide of beta-glucose. ... Look up nucleic acid in Wiktionary, the free dictionary. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... Polynucleotide literally means many nucleotides. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions... [edit] Amino acids and proteins Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds. Many proteins are the enzymes that catalyze the chemical reactions in metabolism. Other proteins have structural or mechanical functions, such as the proteins in the cytoskeleton that form a system of scaffolding to maintain cell shape.[5] Proteins are also important in cell signaling, immune responses, cell adhesion, active transport across membranes and the cell cycle.[6] A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Phenylalanine is one of the standard amino acids. ... A peptide bond is a chemical bond that is formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O). ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... In chemistry and biology, catalysis is the acceleration (increase in rate) of a chemical reaction by means of a substance, called a catalyst, that is itself not consumed by the overall reaction. ... The eukaryotic cytoskeleton. ... This article is about the temporary framework. ... Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. ... Each antibody binds to a specific antigen; an interaction similar to a lock and key. ... Schematic of cell adhesion The study of cell adhesion is part of cell biology. ... 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. ... The cell cycle, or cell-division cycle, is the series of events that take place in a eukaryotic cell leading to its replication. ... [edit] Lipids Lipids are the most diverse group of biochemicals. Their main structural uses are as part of biological membranes such as the cell membrane, or as a source of energy.[6] Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform.[7] The fats are a large group of compounds that contain fatty acids and glycerol; a glycerol molecule attached to three fatty acid esters is a triacylglyceride.[8] Several variations on this basic structure exist, including alternate backbones such as sphingosine in the sphingolipids, and hydrophilic groups such as phosphate in phospholipids. Steroids such as cholesterol are another major class of lipids that are made in cells.[9] Some common lipids. ... A biological membrane or biomembrane is an enclosing or separating tissue which acts as a barrier within or around a cell. ... Look up cell membrane in Wiktionary, the free dictionary. ... Hydrophobe (from the Greek (hydros) water and (phobos) fear) in chemistry refers to the physical property of a molecule that is repelled by water. ... Amphiphile (from the Greek αμφις, amphis: both and φιλíα, philia: love, friendship) is a term describing a chemical compound possessing both hydrophilic and hydrophobic nature. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... For benzine, see petroleum ether. ... R-phrases , , , S-phrases , Flash point Non-flammable U.S. Permissible exposure limit (PEL) 50 ppm (240 mg/m3) (OSHA) Supplementary data page Structure and properties n, εr, etc. ... For other uses, see FAT. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid often with a long unbranched aliphatic tail (chain), which is either saturated or unsaturated. ... “Glycerine” redirects here. ... A carboxylic acid ester. ... Example of an unsaturated fat triglyceride. ... Sphingosine is a compound that forms a primary part of the sphingolipids, a class of cell membrane lipids which includes sphingomyelin, an important phospholipid. ... General chemical structure of sphingolipids. ... Hydrophile, from the Greek (hydros) water and φιλια (philia) friendship, refers to a physical property of a molecule that can transiently bond with water (H2O) through hydrogen bonding. ... A phosphate, in inorganic chemistry, is a salt of phosphoric acid. ... Phospholipid Two schematic representations of a phospholipid. ... This article is about the chemical family of steroids. ... Cholesterol is a sterol (a combination steroid and alcohol), a lipid found in the cell membranes of all body tissues, and is transported in the blood plasma of all animals. ... [edit] Carbohydrates Glucose can exist in both a straight-chain and ring form. Carbohydrates are straight-chain aldehydes or ketones with many hydroxyl groups that can exist as straight chains or rings. Carbohydrates are the most abundant biological molecules, and fill numerous roles, such as the storage and transport of energy (starch, glycogen) and structural components (cellulose in plants, chitin in animals).[6] The basic carbohydrate units are called monosaccharides and include galactose, fructose, and most importantly glucose. Monosaccharides can be linked together to form polysaccharides in almost limitless ways.[10] Image File history File links Glucose_Fisher_to_Haworth. ... Image File history File links Glucose_Fisher_to_Haworth. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... Lactose is a disaccharide found in milk. ... An aldehyde. ... Ketone group A ketone (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... // Hydroxyl group The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. ... Starch (CAS# 9005-25-8, chemical formula (C6H10O5)n,[1]) is a mixture of amylose and amylopectin (usually in 20:80 or 30:70 ratios). ... This article does not cite any references or sources. ... Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a polysaccharide of beta-glucose. ... Structure of the chitin molecule, showing two of the N-Acetylglucosamine units that repeat to form long chains in beta-1,4 linkage. ... Monosaccharides are the simplest form of carbohydrates. ... Galactose (also called brain sugar) is a type of sugar found in dairy products, in sugar beets and other gums and mucilages. ... 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. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... [edit] Nucleotides The polymers DNA and RNA are long chains of nucleotides. These molecules are critical for the storage and use of genetic information, through the processes of transcription and protein biosynthesis.[6] This information is protected by DNA repair mechanisms and propagated through DNA replication. A few viruses have an RNA genome, for example HIV, which uses reverse transcription to create a DNA template from its viral RNA genome.[11] RNA in ribozymes such as spliceosomes and ribosomes is similar to enzymes as it can catalyze chemical reactions. Individual nucleosides are made by attaching a nucleobase to a ribose sugar. These bases are heterocyclic rings containing nitrogen, classified as purines or pyrimidines. Nucleotides also act as coenzymes in metabolic group transfer reactions.[12] The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ... Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... An overview of protein synthesis. ... 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. ... DNA replication. ... This article is about biological infectious particles. ... Species Human immunodeficiency virus 1 Human immunodeficiency virus 2 Human immunodeficiency virus (HIV) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS, a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections). ... Reverse transcriptase is an enzyme used by all retroviruses and retrotransposons that transcribes the genetic information from the virus or retrotransposon from RNA into DNA, which can integrate into the host genome. ... // A ribozyme (from ribonucleic acid enzyme, also called RNA enzyme or catalytic RNA) is an RNA molecule that catalyzes a chemical reaction. ... A spliceosome is a complex of RNA and many protein subunits called snRNPs, that removes the non-coding introns from unprocessed mRNA. Spliceosomes are unique to eukaryotic mRNA as the mRNA of prokaryotes lack introns. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... Nucleosides are glycosylamines made by attaching a nucleobase (often reffered to simply as bases) to a ribose ring. ... Adenine Guanine Thymine Cytosine ... Ribose Ribose, primarily seen as D-ribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... Heterocyclic compounds are substances which contain a ring structure as found in benzene and the aromatic compounds, or aromatic hydrocarbons, but in which other atoms than carbon, such as sulfur, oxygen or nitrogen are found as part of the ring. ... Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring that is fused with an imidazole ring. ... Pyrimidine is a heterocyclic aromatic organic compound, which is similar to benzene and pyridine and that contains two nitrogen atoms at positions 1 and 3 of the six-membered ring. ... [edit] Coenzymes Structure of the coenzyme acetyl-CoA.The transferable acetyl group is bonded to the sulphur atom at the extreme left. Metabolism involves a vast array of chemical reactions, but most fall under a few basic types of reactions that involve the transfer of functional groups.[13] This common chemistry allows cells to use a small set of metabolic intermediates to carry chemical groups between different reactions.[12] These group-transfer intermediates are called coenzymes. Each class of group-transfer reaction is carried out by a particular coenzyme, which is the substrate for a set of enzymes that produce it, and a set of enzymes that consume it. These coenzymes are therefore continuously being made, consumed and then recycled.[14] Image File history File links Acetyl-CoA-2D.svg‎ Please see the file description page for further information. ... Image File history File links Acetyl-CoA-2D.svg‎ Please see the file description page for further information. ... Coenzyme A Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. ... Categories: Biochemistry stubs | Thiols ... Acetyl is the radical of acetic acid. ... In organic chemistry, functional groups (or moieties) are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... Coenzyme A Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. ... For other uses, see Substrate. ... The most central coenzyme is adenosine triphosphate (ATP), the universal energy currency of cells. This nucleotide is used to transfer chemical energy between different chemical reactions. There is only a small amount of ATP in cells, but as it is continuously regenerated, the human body can use about its own weight in ATP per day.[14] ATP acts as a bridge between catabolism and anabolism, with catabolic reactions generating ATP and anabolic reactions consuming it. It also serves as a carrier of phosphate groups in phosphorylation reactions. Adenosine 5-triphosphate (ATP) is a multifunctional nucleotide that is most important as a molecular currency of intracellular energy transfer. ... A nucleotide is a chemical compound that consists of a heterocyclic base, a sugar, and one or more phosphate groups. ... 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 vitamin is an organic compound needed in small quantities that cannot be made in the cells. In human nutrition, most vitamins function as coenzymes after modification; for example, all water-soluble vitamins are phosphorylated or are coupled to nucleotides when they are used in cells.[15] Nicotinamide adenine dinucleotide (NADH), a derivative of vitamin B3 (niacin), is an important coenzyme that acts as a hydrogen acceptor. Hundreds of separate types of dehydrogenases remove electrons from their substrates and reduce NAD+ into NADH. This reduced form of the coenzyme is then a substrate for any of the reductases in the cell that need to reduce their substrates.[16] Nicotinamide adenine dinucleotide exists in two related forms in the cell, NADH and NADPH. The NAD+/NADH form is more important in catabolic reactions, while NADP+/NADPH is used in anabolic reactions. Retinol (Vitamin A) For the record label, see Vitamin Records A vitamin is an organic compound required in tiny amounts for essential metabolic reactions in a living organism. ... The updated USDA food pyramid, published in 2005, is a general nutrition guide for recommended food consumption for humans. ... Nicotinamide adenine dinucleotide (NAD+ or in older notation DPN+) is an important coenzyme found in cells. ... Niacin, also known as nicotinic acid or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair. ... A dehydrogenase is an enzyme that oxidizes a substrate by transferring one or more protons and a pair of electrons to an acceptor, usually NAD/NADP or a flavin coenzyme such as FAD or FMN. Common examples of dehydrogenase enzymes in the TCA cycle are pyruvate dehydrogenase, isocitrate dehydrogenase, and... 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. ... A reductase is an enzyme which lowers the activation energy for a reduction reaction. ... Structure of hemoglobin. The protein subunits are in red and blue, and the iron-containing heme groups in green. From PDB 1GZX. Image File history File links Size of this preview: 600 × 600 pixel Image in higher resolution (1600 × 1600 pixel, file size: 1,006 KB, MIME type: image/png)By Richard Wheeler (Zephyris) 2007. ... Image File history File links Size of this preview: 600 × 600 pixel Image in higher resolution (1600 × 1600 pixel, file size: 1,006 KB, MIME type: image/png)By Richard Wheeler (Zephyris) 2007. ... Structure of hemoglobin. ... 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. ... The Protein Data Bank (PDB) is a repository for 3-D structural data of proteins and nucleic acids. ... [edit] Minerals and cofactors Further information: Physiology, bioinorganic chemistry and iron metabolism Inorganic elements play critical roles in metabolism; some are abundant (e.g. sodium and potassium) while others function at minute concentrations. About 99% of mammals' mass are the elements carbon, nitrogen, calcium, sodium, chlorine, potassium, hydrogen, oxygen and sulfur.[17] The organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen and most of the oxygen and hydrogen is present as water.[17] This article or section does not cite any references or sources. ... Bioinorganic Chemistry is a specialized field that spans the chemistry of metal-containing molecules. ... Human beings use 20 mg of iron each day for the production of new red blood cells, much of which is recycled from old red blood cells. ... For sodium in the diet, see Edible salt. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... For other uses, see Carbon (disambiguation). ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... For other uses, see Calcium (disambiguation). ... For sodium in the diet, see Edible salt. ... General Name, symbol, number chlorine, Cl, 17 Chemical series halogens Group, period, block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 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. ... This article is about the chemical element. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... The abundant inorganic elements act as ionic electrolytes. The most important ions are sodium, potassium, calcium, magnesium, chloride, phosphate, and the organic ion bicarbonate. The maintenance of precise gradients across cell membranes maintains osmotic pressure and pH.[18] Ions are also critical for nerves and muscles, as action potentials in these tissues are produced by the exchange of electrolytes between the extracellular fluid and the cytosol.[19] Electrolytes enter and leave cells through proteins in the cell membrane called ion channels. For example, muscle contraction depends upon the movement of calcium, sodium and potassium through ion channels in the cell membrane and T-tubules.[20] This article is about the electrically charged particle. ... An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. ... For sodium in the diet, see Edible salt. ... General Name, symbol, number potassium, K, 19 Chemical series alkali metals Group, period, block 1, 4, s Appearance silvery white Standard atomic weight 39. ... For other uses, see Calcium (disambiguation). ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. ... A phosphate, in inorganic chemistry, is a salt of phosphoric acid. ... For baking soda, see Sodium bicarbonate In inorganic chemistry, a bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. ... An ion gradient is a concentration gradient of ions, it can be called an electrochemical potential gradient of ions across membranes. ... This article or section does not adequately cite its references or sources. ... For other uses, see PH (disambiguation). ... Nerves (yellow) Nerves redirects here. ... A top-down view of skeletal muscle Muscle (from Latin musculus little mouse [1]) is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ... In some animals, including mammals, the two types of extracellular fluids are interstitial fluid and blood plasma. ... The cytosol (cf. ... Look up cell membrane in Wiktionary, the free dictionary. ... Ion channels are present in the membranes that surround all biological cells. ... A top-down view of skeletal muscle A muscle contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. ... A T-tubule (or Transverse tubule), is a deep invagination of the plasma membrane found in skeletal and cardiac muscle cells. ... The transition metals are usually present as trace elements in organisms, with zinc and iron being most abundant.[21][22] These metals are used in some proteins as cofactors and are essential for the activity of enzymes such as catalase and oxygen-carrier proteins such as hemoglobin.[23] These cofactors are bound tightly to a specific protein; although enzyme cofactors can be modified during catalysis, cofactors always return to their original state after catalysis has taken place. The metal micronutrients are taken up into organisms by specific transporters and bound to storage proteins such as ferritin or metallothionein when not being used.[24][25] In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc, cadmium and mercury. ... Microminerals (also known as trace elements) are micronutrients that are chemical elements. ... 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. ... For other uses, see Iron (disambiguation). ... Catalase (human erythrocyte catalase: PDB 1DGF, EC 1. ... Structure of hemoglobin. ... Cofactor may refer to any of the following: Minor (linear algebra) as an alternative name for the determinant of a smaller matrix than that which it describes Cofactor (biochemistry) is a substance that needs to be present in addition to an enzyme for a certain reaction to take place. ... Ferritin is a globular protein found mainly in the liver, which can store about 4500 iron (Fe3+)ions in a hollow protein shell made of 24 subunits. ... Metallothioneins (MTs) is a family of Cys-rich, low molecular weight (MW ranging from 3500 to 14000 Da) proteins. ... [edit] Catabolism Further information: Catabolism Catabolism is the set of metabolic processes that release energy. These include breaking down and oxidising food molecules as well as reactions that trap the energy in sunlight. The purpose of these catabolic reactions is to provide the energy and components needed by anabolic reactions. The exact nature of these catabolic reactions differ from organism to organism, with organic molecules being used as a source of energy in organotrophs, while lithotrophs use inorganic substrates and phototrophs capture sunlight as chemical energy. However, all these different forms of metabolism depend on redox reactions that involve the transfer of electrons from reduced donor molecules such as organic molecules, water, ammonia, hydrogen sulfide or ferrous ions to acceptor molecules such as oxygen, nitrate or sulphate.[26] In animals these reactions involve complex organic molecules being broken down to simpler molecules, such as carbon dioxide and water. In photosynthetic organisms such as plants and cyanobacteria, these electron-transfer reactions do not release energy, but are used as a way of storing energy absorbed from sunlight.[6] Anabolism is the aspect of metabolism that contributes to growth. ... This page is a candidate to be copied to Wiktionary. ... A lithotroph is a microorganism which uses an inorganic substrate to synthesize all its organic molecules. ... Phototrophs or photoautotrophs are photosynthetic algae, fungi, bacteria and cyanobacteria which build up carbon dioxide and water into organic cell materials using energy from sunlight. ... Prism splitting light High Resolution Solar Spectrum Sunlight in the broad sense is the total spectrum of the electromagnetic radiation given off by the Sun. ... Potential energy can be thought of as energy stored within a physical system. ... 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. ... An organic compound is any of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates and carbon oxides. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... For other uses, see Ammonia (disambiguation). ... Hydrogen sulfide (hydrogen sulphide in British English) is the chemical compound with the formula H2S. This colorless, toxic and flammable gas is responsible for the foul odor of rotten eggs and flatulence. ... Ferrous in chemistry is a term used for the iron with an oxidation number +2. ... 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. ... Trinitrate redirects here. ... Sulfate is the IUPAC name for the SO42- ion, consisting of a central sulfur atom single bonded to four tetrahedrally oriented oxygen atoms. ... An organic compound is any of a large class of chemical compounds whose molecules contain carbon, with exception of carbides, carbonates and carbon oxides. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... The leaf is the primary site of photosynthesis in plants. ... Orders The taxonomy of the Cyanobacteria is currently under revision. ... The most common set of catabolic reactions in animals can be separated into three main stages. In the first, large organic molecules such as proteins, polysaccharides or lipids are digested into their smaller components outside cells. Next, these smaller molecules are taken up by cells and converted to yet smaller molecules, usually acetyl coenzyme A (CoA), which releases some energy. Finally, the acetyl group on the CoA is oxidised to water and carbon dioxide in the citric acid cycle and electron transport chain, releasing the energy that is stored by reducing the coenzyme nicotinamide adenine dinucleotide (NAD+) into NADH. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... Some common lipids. ... 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. ... Overview of the citric acid cycle The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle, after Hans Adolf Krebs who identified the cycle) is a series of chemical reactions of central importance in all living cells that use oxygen as part... The Electron Transport Chain. ... Nicotinamide adenine dinucleotide (NAD+ or in older notation DPN+) is an important coenzyme found in cells. ... [edit] Digestion Further information: Digestion and gastrointestinal tract Macromolecules such as starch, cellulose or proteins cannot be rapidly taken up by cells and need to be broken into their smaller units before they can be used in cell metabolism. Several common classes of enzymes digest these polymers. These digestive enzymes include proteases that digest proteins into amino acids, as well as glycoside hydrolases that digest polysaccharides into monosaccharides. For the industrial process, see anaerobic digestion. ... Upper and Lower gastrointestinal tract The gastrointestinal tract (GI tract), also called the digestive tract, or the alimentary canal, is the system of organs within multicellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. ... Proteases (proteinases, peptidases, or proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. ... Glycoside hydrolases (also called glycosidases) catalyze the hydrolysis of the glycosidic linkage to generate two smaller sugars. ... Microbes simply secrete digestive enzymes into their surroundings,[27][28] while animals only secrete these enzymes from specialized cells in their guts.[29] The amino acids or sugars released by these extracellular enzymes are then pumped into cells by specific active transport proteins.[30][31] For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... 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. ... A simplified outline of the catabolism of proteins, carbohydrates and fats. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Lactose is a disaccharide found in milk. ... For other uses, see FAT. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ... [edit] Energy from organic compounds Further information: Cellular respiration, fermentation, carbohydrate catabolism, fat catabolism and protein catabolism Carbohydrate catabolism is the breakdown of carbohydrates into smaller units. Carbohydrates are usually taken into cells once they have been digested into monosaccharides.[32] Once inside, the major route of breakdown is glycolysis, where sugars such as glucose and fructose are converted into pyruvate and some ATP is generated.[33] Pyruvate is an intermediate in several metabolic pathways, but the majority is converted to acetyl-CoA and fed into the citric acid cycle. Although some more ATP is generated in the citric acid cycle, the most important product is NADH, which is made from NAD+ as the acetyl-CoA is oxidized. This oxidation releases carbon dioxide as a waste product. In anaerobic conditions, glycolysis produces lactate, through the enzyme lactate dehydrogenase re-oxidizing NADH to NAD+ for re-use in glycolysis. An alternative route for glucose breakdown is the pentose phosphate pathway, which reduces the coenzyme NADPH and produces pentose sugars such as ribose, the sugar component of nucleic acids. Cellular respiration was discovered by mad scientist Mr. ... It has been suggested that this article or section be merged with Fermentation (food). ... Carbohydrate catabolism is the breakdown of carbohydrates into smaller units. ... Fatty acids are an important source of energy for many organisms. ... Protein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerisation into new proteins via the use of ribonucleic acids (RNA) and ribosomes. ... Monosaccharides are the simplest form of carbohydrates. ... The word glycolysis is derived from Greek γλυκύς (sweet) and λύσις (rupture). ... Glucose (Glc), a monosaccharide (or simple sugar), is an 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. ... Pyruvic acid (CH3COCO2H) is an alpha-keto acid which plays an important role in biochemical processes. ... Categories: Biochemistry stubs | Thiols ... Overview of the citric acid cycle The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle, after Hans Adolf Krebs who identified the cycle) is a series of chemical reactions of central importance in all living cells that use oxygen as part... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Lactic acid is a chemical compound that plays a role in several biochemical processes. ... Lactate dehydrogenase (LDH) is an enzyme (EC 1. ... 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. ... Nicotinamide adenine dinucleotide (NAD+) Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are two important coenzymes found in cells. ... A pentose is a monosaccharide with five carbon atoms. ... Ribose Ribose, primarily seen as D-ribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... Look up nucleic acid in Wiktionary, the free dictionary. ... Fats are catabolised by hydrolysis to free fatty acids and glycerol. The glycerol enters glycolysis and the fatty acids are broken down by beta oxidation to release acetyl-CoA, which then is fed into the citric acid cycle. Fatty acids release more energy upon oxidation than carbohydrates because carbohydrates contain more oxygen in their structures. Hydrolysis is a chemical reaction or process in which a chemical compound reacts with water. ... Schematic demonstrating mitochondrial fatty acid beta-oxidation and effects of LCHAD deficiency Beta oxidation is the process by which fatty acids, in the form of Acetyl-CoA molecules, are broken down in the mitochondria to generate Acetyl-CoA, the entry molecule for the Krebs Cycle. ... Amino acids are either used to synthesize proteins and other biomolecules, or oxidized to urea and carbon dioxide as a source of energy.[34] The oxidation pathway starts with the removal of the amino group by a transaminase. The amino group is fed into the urea cycle, leaving a deaminated carbon skeleton in the form of a keto acid. Several of these keto acids are intermediates in the citric acid cycle, for example the deamination of glutamate forms α-ketoglutarate.[35] The glucogenic amino acids can also be converted into glucose, through gluconeogenesis (discussed below).[36] Phenylalanine is one of the standard amino acids. ... Urea is an organic compound with the chemical formula (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Nonproprietary Names (rINN) in use in Europe. ... In biochemistry, a transaminase or an aminotransferase is an enzyme that catalyzes a type of reaction between an amino acid and an α-keto acid. ... The reactions of the urea cycle. ... Keto acids are organic acids containing a ketone functional group and a carboxylic acid group. ... Glutamate is the anion of glutamic acid. ... Ketoglutaric acid is used for either of two crystalline keto derivatives C5H6O5 of glutaric acid. ... A glucogenic amino acid is an amino acid that can be converted into glucose through gluconeogenesis. ... Pyruvic acid Oxaloacetic acid Phosphoenolpyruvate Fructose 1,6-bisphosphate Fructose 6-phosphate Glucose-6-phosphate Glucose Gluconeogenesis is the generation of glucose from non-sugar carbon substrates like pyruvate, lactate, glycerol, and amino acids (primarily alanine and glutamine). ... [edit] Oxidative phosphorylation Structure of ATP synthase, the proton channel and rotating stalk are shown in blue and the synthase subunits in red. Further information: Oxidative phosphorylation,