The citric acid cycle—also known as the Krebs cycle, Szent-Györgyi-Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of biochemical reactions to release the energy stored in nutrients through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. The chemical energy released is available under the form of ATP. The Krebs cycle is used by organisms that respire (as opposed to organisms that ferment) to generate energy, either by anaerobic respiration or aerobic respiration. In addition, the cycle provides precursors of certain amino acids, as well as the reducing agent NADH, that are used in numerous other reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest components of metabolism. Even though it is branded as a 'cycle', it is not necessary for metabolites to follow only one specific route; at least three alternative segments of the citric acid cycle have been recognized.
In biochemistry, a transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups from one molecule to another. They are involved in hundreds of different biochemical pathways throughout biology, and are integral to some of life's most important processes.
In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.
Amino acid synthesis is the set of biochemical processes by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids. These 11 are called the non-essential amino acids).
In enzymology, a malonate CoA-transferase is an enzyme that catalyzes the chemical reaction
In enzymology, an indoleacetate—lysine synthetase (EC 6.3.2.20) is an enzyme that catalyzes the chemical reaction
The enzyme pyrazolylalanine synthase (EC 4.2.1.50) catalyzes the chemical reaction
In enzymology, a mimosinase (EC 3.5.1.61) is an enzyme that catalyzes the chemical reaction
In enzymology, a 8-amino-7-oxononanoate synthase (EC 2.3.1.47) is an enzyme that catalyzes the chemical reaction
In enzymology, a glycine C-acetyltransferase is an enzyme that catalyzes the chemical reaction:
In enzymology, a taxadien-5alpha-ol O-acetyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a beta-pyrazolylalanine synthase (EC 2.5.1.51) is an enzyme that catalyzes the chemical reaction
In enzymology, a cysteine synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a N2-(2-carboxyethyl)arginine synthase (EC 2.5.1.66) is an enzyme that catalyzes the chemical reaction
In enzymology, an O-acetylhomoserine aminocarboxypropyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an uracilylalanine synthase (EC 2.5.1.53) is an enzyme that catalyzes the chemical reaction
In enzymology, a zeatin 9-aminocarboxyethyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, an indole-3-acetate beta-glucosyltransferase is an enzyme that catalyzes the chemical reaction
