Metabolism

thumb|upright=1.5|Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant. upright=1.5|thumb|right|Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial [[vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in the ocean and on land, respectively.]]

thumb|400px|The enzyme glucosidase converts the sugar [[maltose into two glucose sugars. Active site residues in red, maltose substrate in black, and NAD cofactor in yellow. ()|alt=Ribbon diagram of glycosidase with an arrow showing the cleavage of the maltose sugar substrate into two glucose products.]]

thumb|upright=1.35|Simplified view of cellular metabolism

digestive system in humans

Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place

thumb|Phylogenetic tree of bacteria and archaea, highlighting those that carry out fermentation. Their end products are also highlighted. Figure modified from Hackmann (2024). Fermentation is a type of anaerobic metabolism that harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and their electrons are transferred to other organic molecules (cofactors, coenzymes, etc.). Anaerobic glycolysis is a related term used to describe the occurrence of fermentation in organisms (

enzymatic release of energy from inorganic and organic compounds

Bilirubin (BR) (adopted from German, originally bili, for bile, plus ruber, Latin for red) is a red-orange compound that occurs as the reduction product of biliverdin, a breakdown product of heme. It is further broken down in the colon to urobilinogen, most of which becomes stercobilin, causing the brown color of feces. Some unconverted urobilinogen, metabolised to urobilin, provides the straw-yellow color in urine.

thumb|Mammals excrete urine through the urinary system. Excretion is elimination of metabolic waste, which is an essential process in all organisms. In vertebrates, this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks after leaving the cell. For example, placental mammals expel urine from the bladder through the urethra, which is part of the excretory system. Unicellular organisms discharge waste products directly through the surface of the cell. Another example would be how mammals release solid waste (f

cellular metabolic process in which a protein is formed, using the sequence of a mature mRNA or circRNA molecule to specify the sequence of amino acids in a polypeptide chain

thumb|Schematic diagram showing anabolism and catabolism Anabolism ( ) is the set of metabolic pathways that construct macromolecules like DNA or RNA from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-down aspect. Anabolism is usually synonymous with biosynthesis.

biogeochemical cycle by which nitrogen is converted into various chemical forms

300px|right|thumb|Basic structure of a peroxisome thumb|300px|Distribution of peroxisomes (white) in HEK 293 cells during [[mitosis]] alt=Peroxisome in rat neonatal cardiomyocyte staining The SelectFX Alexa Fluor 488 Peroxisome Labeling Kit directed against peroxisomal membrane protein 70 (PMP 70)|thumb|Peroxisome in rat neonatal cardiomyocyte

thumb|250px|right|Schematic breakdown of large biomolecules to release energy for fueling the cell [[metabolism by producing ATP, the energy currency of the cell]] thumb|500px|Carbon Catabolism pathway map for free energy including carbohydrate and lipid sources of energy

simplest of the alpha-keto acids

process which converts nitrogen from the air into compounds such as ammonia

thumb|3D structure of a hammerhead ribozyme

phosphorylation of ADP to ATP that accompanies the oxidation of a metabolite through the operation of the respiratory chain

Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass).

right|thumb|Venenivibrio stagnispumantis gains energy by oxidizing hydrogen gas.

Biosynthesis is chemical synthesis occurring in biological contexts. It most often refers to multi-step, enzyme-catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthesis) serve as enzyme substrates, with conversion by the living organism either into simpler or more complex products. Examples of biosynthetic pathways include those for the production of amino acids, lipid membrane components, and nucleotides, but also for the production of all classes of biological macromolecules, and of acetyl-coenzyme A, adenosine triphosphate, nicotinami

thumb|right|class=skin-invert-image|Porphine, the parent of porphyrin

coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle

compound that participates in a chemical reaction that produces another compound

superfamily of enzymes containing heme as a cofactor that function as monooxygenases

molecule that binds to an enzyme and decreases its activity

biological metric

Deamination is the removal of an amino group from a molecule. Enzymes that catalyse this reaction are called deaminases.

Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low glucose availability. In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency. Ketoacidosis is most commonly the result of complete insulin deficiency in type 1 diabetes or late-stage type 2 diabetes. K

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thumb|300px|The hydrolysis of a [[protein (red) by the nucleophilic attack of water (blue). The uncatalysed half-life is several hundred years.]]

Putrefaction is the fifth stage of death, following pallor mortis, livor mortis, algor mortis, and rigor mortis. This process references the breaking down of a body of an animal post-mortem. In broad terms, it can be viewed as the decomposition of proteins, and the eventual breakdown of the cohesiveness between tissues, and the liquefaction of most organs. This is caused by the decomposition of organic matter by bacterial or fungal digestion, which causes the release of gases that infiltrate the body's tissues, and leads to the deterioration of the tissues and organs. The approximate time it

disease that involving errors in metabolic processes of building or degradation of molecules

combination of two biological processes to supply cells with nutrients

biochemical modification of drugs or foreign compounds by living organisms

biogeochemical cycle of sulfur

food produced by a method converting substrates to fermentation end products

chemical compound

class of disease including endocrine diseases, nutritional diseases and metabolic diseases

thumb|The central principle of biology showing the flow of information from [[DNA to the phenotype. Associated with each stage is the corresponding systems biology tool, from genomics to metabolomics.]]

Methylglyoxal (MGO) is the organic compound with the formula CH3C(O)CHO. It is a reduced derivative of pyruvic acid. It is a reactive compound that is implicated in the biology of diabetes. Methylglyoxal is produced industrially by degradation of carbohydrates using overexpressed methylglyoxal synthase.

chemical compound

Porphobilinogen (PBG) is an organic compound that occurs in living organisms as an intermediate in the biosynthesis of porphyrins, which include critical substances like hemoglobin and chlorophyll.

thumb|upright=1.4|General schema showing the relationships of the genome, [[transcriptome, proteome, and metabolome (lipidome, glycome).]]

Stercobilin is a tetrapyrrolic bile pigment and is one end-product of heme catabolism. It is the chemical responsible for the brown color of human feces and was originally isolated from feces in 1932. Stercobilin (and related urobilin) can be used as a marker for biochemical identification of fecal pollution levels in rivers.

Corrin is a heterocyclic compound. Although not known to exist on its own, the molecule is of interest as the parent macrocycle related to the cofactor and chromophore in vitamin B12. Its name reflects that it is the "core" of vitamin B12 (cobalamins). Compounds with a corrin core are known as "corrins".

chemolithotrophic organism(s)

Lithotrophs are a diverse group of organisms using an inorganic substrate (usually of mineral origin) to obtain reducing equivalents for use in biosynthesis (e.g., carbon dioxide fixation) or energy conservation (i.e., ATP production) via aerobic or anaerobic respiration. While lithotrophs in the broader sense include photolithotrophs like plants, chemolithotrophs are exclusively microorganisms; no known macrofauna possesses the ability to use inorganic compounds as electron sources. Macrofauna and lithotrophs can form symbiotic relationships, in which case the lithotrophs are called "prokaryo

metric of alcohol intoxication

waste materials emitted by evacuation from animal organisms

class of enzymes

Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens.

Malonyl-CoA is a coenzyme A derivative of malonic acid.

metabolic reaction that results in the formation of adenosine triphosphate

thumb|right|220px|Carboxypeptidase A, from bovine pancreas A carboxypeptidase (EC number 3.4.16 - 3.4.18) is a protease enzyme that hydrolyzes (cleaves) a peptide bond at the carboxy-terminal (C-terminal) end of a protein or peptide. This is in contrast to an aminopeptidases, which cleave peptide bonds at the N-terminus of proteins. Humans, animals, bacteria and plants contain several types of carboxypeptidases that have diverse functions ranging from catabolism to protein maturation. At least two mechanisms have been discussed.

The chemical reactions and pathways involving fatty acids, aliphatic monocarboxylic acids liberated from naturally occurring fats and oils by hydrolysis.

inhibiting effect of oxygen on the fermentation process

Agmatine, also known as 4-aminobutyl-guanidine, was discovered in 1910 by Albrecht Kossel. It is a chemical substance which is naturally created from the amino acid arginine. Agmatine has been shown to exert modulatory action at multiple molecular targets, notably: neurotransmitter systems, ion channels, nitric oxide (NO) synthesis, and polyamine metabolism and this provides bases for further research into potential pharmacological applications.