Adenosine triphosphate
IUPAC name	5-(6-aminopurin-9-yl) -3,4-dihydroxy-oxolan-2-yl methoxy-hydroxy-phosphoryl oxy-hydroxy-phosphoryl oxyphosphonic acid
Identifiers
CAS number	[56-65-5]
Properties
Molecular formula	C10H16N5O13P3
Molar mass	507.181 g/mol
Acidity (pKa)	6.5
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Adenosine 5'-triphosphate (ATP) is a multifunctional nucleotide that is most important as a "molecular currency" of intracellular energy transfer.^[1] In this role, ATP transports chemical energy within cells for metabolism. It is produced as an energy source during the processes of photosynthesis and cellular respiration and consumed by many enzymes and a multitude of cellular processes including biosynthetic reactions, motility and cell division. In signal transduction pathways, ATP is used as a substrate by kinases that phosphorylate proteins and lipids, as well as by adenylate cyclase, which uses ATP to produce the second messenger molecule cyclic AMP. Image File history File links ATP_structure. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... The acid dissociation constant (Ka), also known as the acidity constant or the acid-ionization constant, is a specific equilibrium constant for the reaction of an acid with its conjugate base in aqueous solution [1]. // When an acid dissolves in water, it partly dissociates forming hydronium ions and its conjugate... The plimsoll symbol as used in shipping In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals exactly). ... A nucleotide is a chemical compound that consists of 3 portions: a heterocyclic base, a sugar, and one or more phosphate groups. ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... 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... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... assimilation. ... Cellular respiration was discovered by mad scientist Mr. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... Biosynthesis is a phenomenon where chemical compounds are produced from simpler reagents. ... Motility is a biological term which refers to the ability to move spontaneously and independently. ... This does not adequately cite its references or sources. ... 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 what is thought of as... For other uses, see Substrate. ... 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 phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein molecule or a small molecule. ... A representation of the 3D structure of myoglobin showing coloured alpha helices. ... Some common lipids. ... Epinephrine binds its receptor, that associates with an heterotrimeric G protein. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay signals within a cell. ... Structure of cAMP cAMP represented in three ways, the left with sticks-representation, the middle with structure formula, and the right with space filled representation. ...

The structure of this molecule consists of a purine base (adenine) attached to the 1' carbon atom of a pentose sugar (ribose). Three phosphate groups are attached at the 5' carbon atom of the pentose sugar. ATP is also incorporated into nucleic acids by polymerases in the processes of DNA replication and transcription. When ATP is used in DNA synthesis, the ribose sugar is first converted to deoxyribose by ribonucleotide reductase. ATP was discovered in 1929 by Karl Lohmann,^[2] and was proposed to be the main energy-transfer molecule in the cell by Fritz Albert Lipmann in 1941.^[3] Purine (1) is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... For the programming language Adenine, see Adenine (programming language). ... 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. ... ITaq DNA polymerase A polymerase (EC 2. ... DNA replication. ... A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... Deoxyribose Deoxyribose, also known as D-Deoxyribose and 2-deoxyribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... Ribonucleotide reductase (RNR) is an enzyme that controls the cellular concentration of deoxyribonucleotides. ... Categories: Stub | Nobel Prize in Physiology or Medicine winners ...

[edit] Physical and chemical properties

ATP consists of adenosine — itself composed of an adenine ring and a ribose sugar — and three phosphate groups (triphosphate). The phosphoryl groups, starting with the group closest to the ribose, are referred to as the alpha (α), beta (β), and gamma (γ) phosphates. ATP is highly soluble in water and is quite stable in solutions between pH 6.8–7.4, but is rapidly hydrolysed at extreme pH. Consequently, ATP is best stored as an anhydrous salt.^[4] Adenosine is a nucleoside composed of adenine attached to a ribose (ribofuranose) moiety via a β-N9-glycosidic bond. ... For the programming language Adenine, see Adenine (programming language). ... Ribose Ribose, primarily seen as D-ribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... A phosphate, in inorganic chemistry, is a salt of phosphoric acid. ... Hydrolysis is a chemical reaction or process in which a chemical compound is broken down by reaction with water. ...

ATP is an unstable molecule and tends to be hydrolysed in water. If ATP and ADP are in chemical equilibrium, almost all the ATP will be converted to ADP. Any system that is far from equilibrium contains potential energy, and is capable of doing work. Biological cells maintain the ratio of ATP to ADP at a point ten orders of magnitude from equilibrium, with ATP concentrations a thousandfold higher than the concentration of ADP. This displacement from equilibrium means that the hydrolysis of ATP in the cell releases a great amount of energy.^[5] ATP is commonly referred to as a "high energy molecule"; however this is incorrect, as a mixture of ATP and ADP at equilibrium in water can do no useful work at all.^{[citation needed]} ATP does not contain "high-energy bonds", and any other unstable molecule would serve equally well as a way of storing energy, if the cell maintained its concentration far from equilibrium.^{[citation needed]} Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... A burette, an apparatus for carrying out acid-base titration, is an important part of equilibrium chemistry. ... Potential energy can be thought of as energy stored within a physical system. ... In thermodynamics, work is the quantity of energy transferred from one system to another without an accompanying transfer of entropy. ...

The amount of energy released can be calculated from the changes in energy under non-natural conditions. The net change in heat energy (enthalpy) at standard temperature and pressure of the decomposition of ATP into hydrated ADP and hydrated inorganic phosphate is −20.5 kJ/mol, with a change in free energy of 3.4 kJ/mol.^[6] The energy released by cleaving either a phosphate (Pi) or pyrophosphate (PPi) unit from ATP, with all reactants and products at their standard states of 1 M concentration, are: t In thermodynamics and molecular chemistry, the enthalpy or heat content (denoted as H or ΔH, or rarely as χ) is a quotient or description of thermodynamic potential of a system, which can be used to calculate the useful work obtainable from a closed thermodynamic system under constant pressure. ... In chemistry and other sciences, STP or standard temperature and pressure is a standard set of conditions for experimental measurements, to enable comparisons to be made between sets of data. ... Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... The thermodynamic free energy is a measure of the amount of mechanical (or other) work that can be extracted from a system, and is helpful in engineering applications. ... The plimsoll symbol as used in shipping In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals exactly). ...

ATP + H₂O → ADP(hydrated) + Pi(hydrated) + H⁺(hydrated) ΔG˚ = -30.54 kJ/mol (−7.3 kcal/mol)

ATP + H₂O → AMP(hydrated) + PPi(hydrated) + H⁺(hydrated) ΔG˚ = -45.6 kJ/mol (−10.9 kcal/mol)

These values can be used to calculate the change in energy under physiological conditions and the cellular ATP/ADP ratio. The values given for the Gibbs free energy for this reaction are dependent on a number of factors, including overall ionic strength and the presence of alkaline earth metal ions such as Mg²⁺ and Ca²⁺. Under typical cellular conditions, ΔG is approximately −57 kJ/mol (−14 kcal/mol).^[7] In thermodynamics, the Gibbs free energy is a thermodynamic potential which measures the useful work obtainable from a closed thermodynamic system at a constant temperature and pressure. ... The alkaline earth metals are a series of elements comprising Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra). ...

[edit] Ionization in biological systems

ATP has multiple ionizable groups with different acid dissociation constants. In neutral solution, ATP is ionized and exists mostly as ATP⁴⁻, with a small proportion of ATP³⁻.^[8] As ATP has several negatively-charged groups in neutral solution, it can chelate metals with very high affinity. The binding constant for various metal ions are (given as per mole) as Mg²⁺ (9 554), Na⁺ (13), Ca²⁺ (3 722), K⁺ (8), Sr²⁺ (1 381) and Li⁺ (25).^[9] Due to the strength of these interactions, ATP exists in the cell mostly in a complex with Mg²⁺.^[10][8] The acid dissociation constant (Ka), also known as the acidity constant or the acid-ionization constant, is a specific equilibrium constant for the reaction of an acid with its conjugate base in aqueous solution [1]. // When an acid dissolves in water, it partly dissociates forming hydronium ions and its conjugate... Chelation (from Greek χηλή, chelè, meaning claw; pronounced ) is the binding or complexation of a bi- or multidentate ligand. ... The binding constant is a special case of the equilibrium constant K. The equilibrium state of molecular binding, i. ... 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. ... For sodium in the diet, see Salt. ... For other uses, see Calcium (disambiguation). ... 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 strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... This article is about the chemical element named Lithium. ...

[edit] Biosynthesis

The ATP concentration inside the cell is typically 1 - 10 mM.^[11] ATP can be produced by redox reactions using simple and complex sugars (carbohydrates) or lipids as an energy source. For ATP to be synthesized from complex fuels, they first need to be broken down into their basic components. Carbohydrates are hydrolysed into simple sugars, such as glucose and fructose. Fats (triglycerides) are metabolised to give fatty acids and glycerol. For other uses, see Concentration (disambiguation). ... This page refers to concentration in the chemical sense. ... ed|other uses|reduction}} Illustration of a redox reaction Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... This article deals with sugar as food and as an important, widely traded commodity; the word also has other uses; see Sugar (disambiguation) A sugar is a form of carbohydrate; the most commonly used sugar is a white crystalline solid, sucrose; used to alter the flavor and properties (mouthfeel, perservation... Carbohydrates (literally hydrates of carbon) are chemical compounds that act as the primary biological means of storing or consuming energy, other forms being fat and protein. ... Figure 1: Basic lipid structure. ... Hydrolysis is a chemical reaction or process in which a chemical compound is broken down by reaction with water. ... 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. ... {{refimprove|date=October 2007} Ausra yra maza mergaite. ... 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. ... Glycerine, Glycerin redirects here. ...

The overall process of oxidizing glucose to carbon dioxide is known as cellular respiration and can produce up to 36 molecules of ATP from a single molecule of glucose.^[12] ATP can be produced by a number of distinct cellular processes; the three main pathways used to generate energy in eukaryotic organisms are glycolysis and the citric acid cycle/oxidative phosphorylation , both components of cellular respiration; and beta-oxidation. The majority of this ATP production by a non-photosynthetic aerobic eukaryote takes place in the mitochondria, which can make up nearly 25% of the total volume of a typical cell.^[12] Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Cellular respiration was discovered by mad scientist Mr. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Glycolysis is the sequence of reactions that converts glucose into pyruvate with the concomitant production of a relatively small amount of ATP. The word is derived from Greek γλυκύς (sweet) and λύσις (letting loose). ... 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 in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. ... Cellular respiration was discovered by mad scientist Mr. ... 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 Acyl-CoA molecules, are broken down in the mitochondria and/or in peroxisomes to generate Acetyl-CoA, the entry molecule for the Krebs Cycle. ... Leaf. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ...

[edit] Glycolysis

Main article: glycolysis

In glycolysis, glucose and glycerol are metabolized to pyruvate via the glycolytic pathway. In most organisms this process occurs in the cytosol, but in some protozoa such as the kinetoplastids, this is carried out in a specialized organelle called the glycosome.^[13] Glycolysis generates a net two molecules of ATP through substrate phosphorylation catalyzed by two enzymes: PGK and pyruvate kinase. Two molecules of NADH are also produced, which can be oxidized via the electron transport chain and result in the generation of additional ATP by ATP synthase. The pyruvate generated as an end-product of glycolysis is a substrate for the Krebs Cycle. Glycolysis is the sequence of reactions that converts glucose into pyruvate with the concomitant production of a relatively small amount of ATP. The word is derived from Greek γλυκύς (sweet) and λύσις (letting loose). ... Pyruvate (CH3COCOO−) is the ionized form of pyruvic acid. ... The cytosol (cf. ... Orders Trypanosomatida Bodonida The kinetoplastids are a group of flagellate protozoa, including a number of parasites responsible for serious diseases in humans and other animals, as well as various forms found in soil and aquatic environments. ... Schematic of typical animal cell, showing subcellular components. ... The glycosome is a membrane-bound organelle that contains the glycolytic enzymes. ... Substrate-level phosphorylation is a type of chemical reaction that results in the formation of adenosine triphosphate (ATP) by the direct transfer of a phosphate group to adenosine diphosphate (ADP) from a reactive intermediate. ... Phosphoglycerate kinase is a transferase enzyme used in the seventh step of glycolysis. ... Pyruvate kinase is an enzyme involved in glycolysis. ... Nicotinamide adenine dinucleotide (NAD+) Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are two important coenzymes found in cells. ... The Electron Transport Chain. ... An ATP synthase (EC 3. ... The citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle) is a series of chemical reactions of central importance in all living cells that utilize oxygen as part of cellular respiration. ...

[edit] Citric acid cycle

Main articles: Citric acid cycle and oxidative phosphorylation

In the mitochondrion, pyruvate is oxidized by the pyruvate dehydrogenase complex to acetyl CoA, which is fully oxidized to carbon dioxide by the citric acid cycle (also known as the Krebs Cycle). Every "turn" of the citric acid cycle produces two molecules of carbon dioxide, one molecule of the ATP equivalent guanosine triphosphate (GTP) through substrate-level phosphorylation catalyzed by succinyl CoA synthetase, three molecules of the reduced coenzyme NADH, and one molecule of the reduced coenzyme FADH₂. Both of these latter molecules are recycled to their oxidized states (NAD⁺ and FAD, respectively) via the electron transport chain, which generates additional ATP by oxidative phosphorylation. The oxidation of an NADH molecule results in the synthesis of about 3 ATP molecules, and the oxidation of one FADH₂ yields about 2 ATP molecules.^[14] The majority of cellular ATP is generated by this process. Although the citric acid cycle itself does not involve molecular oxygen, it is an obligately aerobic process because O₂ is needed to recycle the reduced NADH and FADH₂ to their oxidized states. In the absence of oxygen the citric acid cycle will cease to function due to the lack of available NAD⁺ and FAD.^[12] 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 in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that transform pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. ... Acetyl-CoA is an important molecule in metabolism, used in many biochemical reactions. ... Carbon dioxide is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... Guanosine triphosphate (GTP) is also known as guanosine-5-triphosphate. ... Substrate-level phosphorylation is a type of chemical reaction that results in the formation of adenosine triphosphate (ATP) by the direct transfer of a phosphate group to adenosine diphosphate (ADP) from a reactive intermediate. ... Coenzyme A Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. ... Nicotinamide adenine dinucleotide (NAD+) Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are two important coenzymes found in cells. ... Riboflavin Flavin is a vaginal ring whose biochemical smell is pungent. ... For other uses, see FAD (disambiguation). ... The Electron Transport Chain. ... The electron transport chain in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. ... This article is about the chemical element and its most stable form, or dioxygen. ... This article or section should be merged with aerobic metabolism. ...

The generation of ATP by the mitochondrion from cytosolic NADH relies on the malate-aspartate shuttle (and to a lesser extent, the glycerol-phosphate shuttle) because the inner mitochondrial membrane is impermeable to NADH and NAD⁺. Instead of transferring the generated NADH, a malate dehydrogenase enzyme converts oxaloacetate to malate, which is translocated to the mitochondrial matrix. Another malate dehydrogenase-catalyzed reaction occurs in the opposite direction, producing oxaloacetate and NADH from the newly transported malate and the mitochondrion's interior store of NAD⁺. A transaminase converts the oxaloacetate to aspartate for transport back across the membrane and into the intermembrane space.^[12] The malate-aspartate shuttle (sometimes also the malate shuttle) is a system of two antiporter proteins located in the inner membrane of the mitochondrion in eukaryotes. ... The glycerol-3-phosphate shuttle is a mechanism that regenerates NAD+ from NADH, a by-product of glycolysis. ... Categories: Biochemistry stubs | EC 1. ... Malate (O−OC-CH2-CH(OH)-COO−) is the ionized form of malic acid. ... 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. ... Aspartic acid, also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ...

In oxidative phosphorylation, the passage of electrons from NADH and FADH₂ through the electron transport chain powers the pumping of protons out of the mitochondrial matrix and into the intermembrane space. This creates a proton motive force that is the net effect of a pH gradient and an electric potential gradient across the inner mitochondrial membrane. Flow of protons down this potential gradient — that is, from the intermembrane space to the matrix — provides the driving force for ATP synthesis by ATP synthase. This enzyme contains a rotor subunit that physically rotates relative to the static portions of the protein during ATP synthesis.^[15] For other uses, see Proton (disambiguation). ... Electrochemical gradients in cellular biology refers to the electrical and chemical properties across a membrane. ... For other uses, see PH (disambiguation). ... This article does not cite any references or sources. ... An ATP synthase (EC 3. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ...

Most of the ATP synthesized in the mitochondria will be used for cellular processes in the cytosol; thus it must be exported from its site of synthesis in the mitochondrial matrix. The inner membrane contains an antiporter, the ADP/ATP translocase, which is an integral membrane protein used to exchange newly-synthesized ATP in the matrix for ADP in the intermembrane space.^[16] This translocase is driven by the membrane potential, as it results in the movement of about 4 negative charges out of the mitochondrial membrane in exchange for 3 negative charges moved inside. However, it is also necessary to transport phosphate into the mitochondrion; the phosphate carrier moves a proton in with each phosphate, partially dissipating the proton gradient. An antiporter is an integral membrane protein that is involved in secondary active transport. ... An Integral Membrane Protein (IMP) is a protein molecule (or assembly of proteins) that is permanently attached to the biological membrane. ...

[edit] Beta-oxidation

Main article: beta-oxidation

Fatty acids can also be broken down to acetyl-CoA by beta-oxidation. Each round of this cycle reduces the length of the acyl chain by two carbon atoms and produces one NADH and one FADH₂ molecule, which are used to generate ATP by oxidative phosphorylation. Because NADH and FADH₂ are energy-rich molecules, dozens of ATP molecules can be generated by the beta-oxidation of a single long acyl chain. The high energy yield of this process and the compact storage of fat explain why it is the most dense source of dietary calories.^[17] 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 Acyl-CoA molecules, are broken down in the mitochondria and/or in peroxisomes to generate Acetyl-CoA, the entry molecule for the Krebs Cycle. ... Categories: Biochemistry stubs | Thiols ... 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 Acyl-CoA molecules, are broken down in the mitochondria and/or in peroxisomes to generate Acetyl-CoA, the entry molecule for the Krebs Cycle. ... Etymology: French calorie, from Latin calor (heat), from calere (to be warm). ...

[edit] Anaerobic respiration

Main article: anaerobic respiration

Anaerobic respiration or fermentation entails the generation of energy via the process of oxidation in the absence of O₂ as an electron acceptor. In most eukaryotes, glucose is used as both an energy store and an electron donor. The equation for the oxidation of glucose to lactic acid is: Anaerobic respiration refers to the oxidation of molecules in the absence of oxygen to produce energy, in opposition to Aerobic respiration which does use oxygen. ... For other uses, see Fermentation. ... The most fundamental reactions in chemistry are the redox processes. ... This article is about the chemical element and its most stable form, or dioxygen. ... An electron acceptor is a chemical entity that accepts electrons transferred to it from another compound. ... For the production of milk by mammals, see Lactation. ...

C₆H₁₂O₆ 2CH₃CH(OH)COOH + 2 ATP

In prokaryotes, multiple electron acceptors can be used in anaerobic respiration. These include nitrate, sulfate or carbon dioxide. These processes lead to the ecologically-important processes of denitrification, sulfate reduction and acetogenesis, respectively.^[18][19] Trinitrate redirects here. ... The sulfate anion, SO42− The structure and bonding of the sulfate ion In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ... This does not cite its references or sources. ... Acetogenesis is a process through which acetate is produced by anaerobic bacteria from a variety of energy (for example, hydrogen) and carbon (for example, carbon dioxide) sources. ...

[edit] ATP replenishment by nucleoside diphosphate kinases

ATP can also be synthesized through several so-called "replenishment" reactions catalyzed by the enzyme families of nucleoside diphosphate kinases (NDKs), which use other nucleoside triphosphates as a high-energy phosphate donor, and the ATP:guanido-phosphotransferase family, which uses creatine. Nucleoside-diphosphate kinases (NDKs, also nucleoside diphosphate kinases and nucleoside diphosphokinases) are enzymes which catalyzes the exchange of phosphate groups between different nucleoside diphosphates. ... For the use of creatine to enhance athletic performance, please see Creatine supplements. ...

ADP + GTP ATP + GDP

Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... Guanosine triphosphate (GTP) is also known as guanosine-5-triphosphate. ...

[edit] ATP production during photosynthesis

In plants, ATP is synthesized in thylakoid membrane of the chloroplast during the light-dependent reactions of photosynthesis in a process called photophosphorylation. Here, light energy is used to pump protons across the chloroplast membrane. This produces a proton-motive force and this drives the ATP synthase, exactly as in oxidative phosphorylation.^[20] Some of the ATP produced in the chloroplasts is consumed in the Calvin cycle, which produces triose sugars. A thylakoid is a phospholipid bilayer membrane internal to chloroplasts. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Light-dependent reactions of photosynthesis at the thylakoid membrane The initial stage of the photosynthetic system is the light-dependent reaction, which converts solar energy into chemical energy. ... assimilation. ... Overview of the Calvin cycle and carbon fixation The Calvin cycle (or Calvin-Benson cycle or carbon fixation) is a series of biochemical reactions that takes place in the stroma of chloroplasts in photosynthetic organisms. ... A triose is a monosaccharide containing three carbon atoms. ...

[edit] ATP recycling

The total quantity of ATP in the human body is about 0.1 mole. The majority of ATP is not usually synthesised de novo, but is generated from ADP by the aforementioned processes. Thus, at any given time, the total amount of ATP + ADP remains fairly constant. The mole (symbol: mol) is the SI base unit that measures an amount of substance. ...

The energy used by human cells requires the hydrolysis of 100 to 150 moles of ATP daily which is around 50 to 75 kg. Typically, a human will use up their body weight of ATP over the course of the day.^[21] This means that each ATP molecule is recycled 1000 to 1500 times during a single day (100 / 0.1 = 1000). ATP cannot be stored, hence its consumption closely follows its synthesis. Hydrolysis is a chemical reaction or process in which a chemical compound is broken down by reaction with water. ...

[edit] Regulation of biosynthesis

ATP production in an aerobic eukaryotic cell is tightly regulated by allosteric mechanisms, by feedback effects, and by the substrate concentration dependence of individual enzymes within the glycolysis and oxidative phosphorylation pathways. Key control points occur in enzymatic reactions that are so energetically favorable that they are effectively irreversible under physiological conditions. 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. ... For other uses, see Feedback (disambiguation). ...

In glycolysis, hexokinase is directly inhibited by its product, glucose-6-phosphate, and pyruvate kinase is inhibited by ATP itself. The main control point for the glycolytic pathway is phosphofructokinase (PFK), which is allosterically inhibited by high concentrations of ATP and activated by high concentrations of AMP. The inhibition of PFK by ATP is unusual, since ATP is also a substrate in the reaction catalyzed by PFK; the biologically active form of the enzyme is a tetramer that exists in two possible conformations, only one of which binds the second substrate fructose-6-phosphate (F6P). The protein has two binding sites for ATP - the active site is accessible in either protein conformation, but ATP binding to the inhibitor site stabilizes the conformation that binds F6P poorly.^[14] A number of other small molecules can compensate for the ATP-induced shift in equilibrium conformation and reactivate PFK, including cyclic AMP, ammonium ions, inorganic phosphate, and fructose 1,6 and 2,6 biphosphate.^[14] A hexokinase is an enzyme that phosphorylates a six-carbon sugar, a hexose, to a hexose phosphate. ... Pyruvate kinase is an enzyme involved in glycolysis. ... Phosphofructokinase (PFK) is the most important regulatory enzyme (EC 2. ... A tetramer is a protein with four subunits (tetrameric). ... A binding site is a region on a protein to which specific ligands bind. ... The active site of an enzyme is the binding site where catalysis occurs. ... Structure of cAMP Cyclic adenosine monophosphate (cAMP, cyclic AMP or 3-5-cyclic adenosine monophosphate) is a molecule that is important in many biological processes; it is derived from adenosine triphosphate (ATP). ... A ball-and-stick model of the ammonium cation Ammonium is also an old name for the Siwa Oasis in western Egypt. ...

The citric acid cycle is regulated mainly by the availability of key substrates, particularly the ratio of NAD⁺ to NADH and the concentrations of calcium, inorganic phosphate, ATP, ADP, and AMP. Citrate - the molecule that gives its name to the cycle - is a feedback inhibitor of citrate synthase and also inhibits PFK, providing a direct link between the regulation of the citric acid cycle and glycolysis.^[14] For other uses, see Calcium (disambiguation). ... Chemical strucutre of citric acid. ... The enzyme citrate synthase (E.C. 2. ...

In oxidative phosphorylation, the key control point is the reaction catalyzed by cytochrome c oxidase, which is regulated by the availability of its substrate—the reduced form of cytochrome c. The amount of reduced cytochrome c available is directly related to the amounts of other substrates: Cytochrome c oxidase The enzyme cytochrome c oxidase (PDB 2OCC, EC 1. ... Cytochrome c with heme c. ...

which directly implies this equation:

Thus, a high ratio of [NADH] to [NAD⁺] or a low ratio of [ADP][P_i] to [ATP] imply a high amount of reduced cytochrome c and a high level of cytochrome c oxidase activity.^[14] An additional level of regulation is introduced by the transport rates of ATP and NADH between the mitochondrial matrix and the cytoplasm.^[16]

[edit] Functions in cells

ATP is generated in the cell by energy-consuming processes and is broken down by energy-releasing processes. In this way ATP transfers energy between spatially-separate metabolic reactions. ATP is the main energy source for the majority of cellular functions. This includes the synthesis of macromolecules, including DNA, RNA, and proteins. ATP also plays a critical role in the transport of macromolecules across cell membranes, e.g. exocytosis and endocytosis. Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... DNA replication. ... 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). ... Neuron A (transmitting) to neuron B (receiving) 1. ... Endocytosis (IPA: ) is a process whereby cells absorb material (molecules such as proteins) from the outside by engulfing it with their cell membrane. ...

In the synthesis of the nucleic acid RNA, ATP is one of the four nucleotides incorporated directly into RNA molecules by RNA polymerases. The energy driving this polymerization comes from cleaving off a pyrophosphate (two phosphate groups).^[22] The process is similar in DNA biosynthesis, except that ATP is reduced to the deoxyribonucleotide dATP, before incorporation into DNA. Look up nucleic acid in Wiktionary, the free dictionary. ... For other uses, see RNA (disambiguation). ... This article does not cite any references or sources. ... A deoxyribonucleotide is the monomer, or single unit, of DNA, or deoxyribonucleic acid. ...

ATP is critically involved in maintaining cell structure by facilitating assembly and disassembly of elements of the cytoskeleton. In a related process, ATP is required for the shortening of actin and myosin filament crossbridges required for muscle contraction. This latter process is one of the main energy requirements of animals and is essential for locomotion and respiration. The eukaryotic cytoskeleton. ... The sliding filament mechanism is a process used by muscles to contract. ... 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. ... In biology and physics, animal locomotion is the study of how animals move, and is part of biophysics. ... The Respiratory System Among four-legged animals, the respiratory system generally includes tubes, such as the bronchi, used to carry air to the lungs, where gas exchange takes place. ...

[edit] Cell signaling

[edit] Extracellular signaling

ATP is also a signaling molecule. ATP, ADP, or adenosine are recognized by purinergic receptors. Nitric oxide is a quite salient signaling molecule, instrumental in both learning and memory. ... Purinergic receptors are a family of newly characterized plasma membrane molecules involved in several and as yet only partially known cellular functions such as vascular reactivity, apoptosis and cytokine secretion. ...

In humans, this signaling role is important in both the central and peripheral nervous system. Activity-dependent release of ATP from synapses, axons and glia activates purinergic membrane receptors known as P2.^[23] The P2Y receptors are metabotropic, i.e. G protein-coupled and modulate mainly intracellular calcium and sometimes cyclic AMP levels. Fifteen members of the P2Y family have been reported (P2Y1–P2Y15), although some are only related through weak homology and several (P2Y5, P2Y7, P2Y9, P2Y10) do not function as receptors that raise cytosolic calcium. The P2X ionotropic receptor subgroup comprises seven members (P2X1–P2X7) which are ligand-gated Ca²⁺-permeable ion channels that open when bound to an extracellular purine nucleotide. In contrast to P2 receptors (agonist order ATP > ADP > AMP > ADO), purinergic nucleotides like ATP are not strong agonists of P1 receptors which are strongly activated by adenosine and other nucleosides (ADO > AMP > ADP > ATP). P1 receptors have A1, A2a, A2b, and A3 subtypes ("A" as a remnant of old nomenclature of adenosine receptor), all of which are G protein-coupled receptors, A1 and A3 being coupled to Gi, and A2a and A2b being coupled to Gs.^[24] A Mu-opioid G protein-coupled receptor with its agonist Figure 1. ... A nucleotide is a chemical compound that consists of 3 portions: a heterocyclic base, a sugar, and one or more phosphate groups. ... Adenosine is a nucleoside composed of adenine attached to a ribose (ribofuranose) moiety via a β-N9-glycosidic bond. ... Nucleosides are glycosylamines made by attaching a nucleobase (often reffered to simply as bases) to a ribose ring. ...

[edit] Intracellular signaling

ATP is critical in signal transduction processes. It is used by kinases as the source of phosphate groups in their phosphate transfer reactions. Kinase activity on substrates such as proteins or membrane lipids are a common form of signal transduction. Phosphorylation of a protein by a kinase can activate this cascade such as the mitogen-activated protein kinase cascade.^[25] 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 what is thought of as... 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 phosphorylated serine residue Phosphorylation is the addition of a phosphate (PO4) group to a protein molecule or a small molecule. ... In cell biology, mitogen-activated protein kinases (MAPKs) are serine/threonine-specific protein kinases that respond to extracellular stimuli and regulate various cellular activities, such as gene expression, mitosis, differentiation, and cell survival/apoptosis. ...

ATP is also used by adenylate cyclase and is transformed to the second messenger molecule cyclic AMP, which is involved in triggering calcium signals by the release of calcium from intracellular stores.^[26] This form of signal transduction is particularly important in brain function, although it is involved in the regulation of a multitude of other cellular processes.^[27] Epinephrine binds its receptor, that associates with an heterotrimeric G protein. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay signals within a cell. ...

[edit] Deoxyribonucleotide synthesis

In all known organisms, the deoxyribonucleotides that make up DNA are synthesized by the action of ribonucleotide reductase (RNR) enzymes on their corresponding ribonucleotides.^[28] This enzyme reduces the 2' hydroxyl group on the ribose sugar to deoxyribose, forming a deoxyribonucleotide (denoted dATP). All ribonucleotide reductase enzymes use a common sulfhydryl radical mechanism reliant on reactive cysteine residues that oxidize to form disulfide bonds in the course of the reaction.^[28] RNR enzymes are recycled by reaction with thioredoxin or glutaredoxin.^[14] 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. ... Ribonucleotide reductase (RNR) is an enzyme that controls the cellular concentration of deoxyribonucleotides. ... // Hydroxyl group The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. ... Ribose Ribose, primarily seen as D-ribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... Deoxyribose Deoxyribose, also known as D-Deoxyribose and 2-deoxyribose, is an aldopentose — a monosaccharide containing five carbon atoms, and including an aldehyde functional group. ... In organic chemistry, a sulfhydryl group or thiol group is a functional group composed of a sulfur and a hydrogen atom (-SH). ... In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ... Cysteine is a naturally occurring, sulfur-containing amino acid that is found in most proteins, although only in small quantities. ... In chemistry, a disulfide bond is a single covalent bond derived from the coupling of thiol groups. ... Thioredoxins are small proteins involved in thiol-redox processes. ... Glutaredoxins are small redox-active proteins related to thioredoxin. ...

The regulation of RNR and related enzymes maintains a balance of dNTPs relative to each other and relative to NTPs in the cell. Very low dNTP concentration inhibits DNA synthesis and DNA repair and is lethal to the cell, while an abnormal ratio of dNTPs is mutagenic due to the increased likelihood of the DNA polymerase incorporating the wrong dNTP during DNA synthesis.^[14] Regulation of or differential specificity of RNR has been proposed as a mechanism for alterations in the relative sizes of intracellular dNTP pools under cellular stress such as hypoxia.^[29] DNA replication. ... 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. ... In biology, a mutagen (Latin, literally origin of change) is a physical or chemical agent that changes the genetic information (usually DNA) of an organism and thus increases the number of mutations above the natural background level. ... 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. ... Hypoxia is a pathological condition in which the body as a whole (generalised hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ...

[edit] Binding to proteins

An example of the Rossmann fold, a structural domain of a decarboxylase enzyme from the bacterium Staphylococcus epidermidis (PDB ID 1G5Q) with a bound flavin mononucleotide cofactor.

Some proteins that bind ATP do so in a characteristic protein fold known as the Rossmann fold, which is a general nucleotide-binding structural domain that can also bind the cofactor NAD.^[30] The most common ATP-binding proteins, known as kinases, share a small number of common folds; the protein kinases, the largest kinase superfamily, all share common structural features specialized for ATP binding and phosphate transfer.^[31] Image File history File links Download high-resolution version (851x734, 232 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Adenosine triphosphate Rossmann fold ... Image File history File links Download high-resolution version (851x734, 232 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Adenosine triphosphate Rossmann fold ... Within a protein, a structural domain (domain) is an element of overall structure that is self-stabilizing and often folds independently of the rest of the protein chain. ... Carboxy-lyases, also known as decarboxylases, are carbon-carbon lyases that add or remove a carboxyl group from organic compounds. ... Binomial name (Winslow & Winslow 1908) Evans 1916 Staphylococcus epidermidis is a member of the bacterial genus Staphylococcus, consisting of Gram-positive cocci arranged in clusters. ... Flavin mononucleotide or FMN is derived from riboflavin (vitamin B2) and functions as cofactor of various oxidoreductases. ... In biochemistry and chemistry, the tertiary structure of a protein or any other macromolecule is its three-dimensional structure, as defined by the atomic coordinates. ... An example of the Rossmann fold, a structural domain of a decarboxylase protein from the bacterium Staphylococcus epidermidis (PDB ID 1G5Q) with the bound flavin mononucleotide cofactor shown. ... A nucleotide is a chemical compound that consists of 3 portions: a heterocyclic base, a sugar, and one or more phosphate groups. ... Within a protein, a structural domain (domain) is an element of overall structure that is self-stabilizing and often folds independently of the rest of the protein chain. ... Nicotinamide adenine dinucleotide (NAD+ or in older notation DPN+) is an important coenzyme found in cells. ... In biochemistry, a kinase is a type of enzyme that transfers phosphate groups from, for example, ATP to a specified substrate or target; the process is termed phosphorylation. Typically, the target is activated or energized by being phosphorylated. ... A protein kinase is an enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). ...

ATP in complexes with proteins generally requires the presence of a divalent cation, almost always magnesium, which binds to the ATP phosphate groups. The presence of magnesium greatly decreases the dissociation constant of ATP from its protein binding partner without affecting the ability of the enzyme to catalyze its reaction once the ATP has bound.^[32] The presence of magnesium ions can serve as a mechanism for kinase regulation.^[33] In chemistry, divalent anions are atoms or radicals with 2 additional electrons when compared to their elemental state (that is, with 2 more electrons than protons); for instance, S-- is the sulfide anion. ... A cation is an ion with positive charge. ... 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. ... In chemistry and biochemistry, a dissociation constant or an ionization constant is a specific type of equilibrium constant used for reversible reactions or processes. ...

[edit] ATP analogs

Biochemistry laboratories often use in vitro studies to explore ATP-dependent molecular processes. Enzyme inhibitors of ATP-dependent enzymes such as kinases are needed to examine the binding sites and transition states involved in ATP-dependent reactions. ATP analogs are also used in X-ray crystallography to determine a protein structure in complex with ATP, often together with other substrates. Most useful ATP analogs cannot be hydrolyzed as ATP would be; instead they trap the enzyme in a structure closely related to the ATP-bound state. Adenosine 5'-(gamma-thiotriphosphate) is an extremely common ATP analog in which one of the gamma-phosphate oxygens is replaced by a sulfur atom; this molecule is hydrolyzed at a dramatically slower rate than ATP itself and functions as an inhibitor of ATP-dependent processes. In crystallographic studies, hydrolysis transition states are modeled by the bound vanadate ion. However, caution is warranted in interpreting the results of experiments using ATP analogs, since some enzymes can hydrolyze them at appreciable rates at high concentration.^[34] In vitro (Latin: within the glass) refers to the technique of performing a given experiment in a test tube, or, generally, in a controlled environment outside a living organism. ... HIV protease in a complex with the protease inhibitor ritonavir. ... 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 binding site is a region on a protein to which specific ligands bind. ... The transition state of a chemical reaction is a particular configuration along the reaction coordinate. ... 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. ... 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. ... This article is about the chemical element. ... Vanadium(V) oxide (V2O5), commonly known as vanadium pentoxide, is the most important compound of vanadium. ...

[edit] See also

• Adenosine diphosphate (ADP)
• Adenosine monophosphate (AMP)
• Cyclic adenosine monophosphate (cAMP)
• ATPases
• ATP hydrolysis
• Citric acid cycle (also called the Krebs cycle or TCA cycle)
• Phosphagen
• Nucleotide exchange factor
• Mitochondria
• Photophosphorylation

Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... Adenosine monophosphate, also known as 5-adenylic acid and abbreviated AMP, is a nucleotide that is found in RNA. It is an ester of phosphoric acid with the nucleoside adenosine. ... Structure of cAMP cAMP represented in three ways, the left with sticks-representation, the middle with structure formula, and the right with space filled representation. ... ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion. ... This is the reaction by which chemical energy that has been stored and transported in the high-energy phosphodiester bonds in ATP is released, for example in the muscles, to produce work. ... 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 phosphagens are energy storage compounds, also known as high energy phosphate compounds, are chiefly found in muscular tissue in animals. ... Nucleotide exchange factors (NEFs) are proteins that stimulate the exchange (replacement) of nucleoside diphosphates for nucleoside triphosphates bound to other proteins. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... The production of ATP using the energy of sunlight is called photophosphorylation. ...

[edit] References