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In addition, acetyl-CoA is a precursor for the biosynthesis of various acetyl-chemicals, acting as an intermediate to transfer an acetyl group during the biosynthesis of those acetyl-chemicals. Acetyl-CoA is also involved in the regulation of various cellular mechanisms by providing acetyl groups to target amino acid residues for post ...
Acetyl Co-A can also be used in fatty acid synthesis, and a common function of the synthetase is to produce acetyl Co-A for this purpose. [3] The reaction catalyzed by acetyl-CoA synthetase takes place in two steps. First, AMP must be bound by the enzyme to cause a conformational change in the active site, which allows the reaction to take place.
Its acetyl-coenzyme A form is the primary input in the citric acid cycle and is obtained from glycolysis, amino acid metabolism, and fatty acid beta oxidation. This process is the body's primary catabolic pathway and is essential in breaking down the building blocks of the cell such as carbohydrates , amino acids , and lipids .
In this system, the substances being transported are malate and citrate. The starting material is acetyl-CoA. It is a molecule that is involved in ATP synthesis, protein metabolism, and lipid metabolism. [6] As the inner membrane is not permeable to this molecule, acetyl-CoA needs to be converted into other products for effective transport. [7]
Two specific enzymes participate on the carbon monoxide side of the pathway: CO dehydrogenase and acetyl-CoA synthase. The former catalyzes the reduction of the CO 2 and the latter combines the resulting CO with a methyl group to give acetyl-CoA. [2] [1] [3] Some anaerobic bacteria use the Wood–Ljungdahl pathway in reverse to break down acetate.
The sole carbon feed stock of the pathway is acetyl-CoA. The first step condenses two acetyl-CoA molecules to yield acetoacetyl-CoA. This is followed by a second condensation to form HMG-CoA (3-hydroxy-3- methyl-glutaryl-CoA). Reduction of HMG-CoA yields (R)-mevalonate. These first 3 enzymatic steps are called the upper mevalonate pathway. [4]
The systematic name of this enzyme class is acetyl-CoA:[acyl-carrier-protein] S-acetyltransferase. Other names in common use include acetyl coenzyme A-acyl-carrier-protein transacylase, acetyl-CoA:ACP transacylase, [acyl-carrier-protein]acetyltransferase, [ACP]acetyltransferase, and ACAT. This enzyme participates in fatty acid biosynthesis.
This four step process repeats until acyl-CoA has removed all carbons from the chain, leaving only Acetyl-CoA. During one cycle of beta oxidation, Acyl-CoA creates one molecule of Acetyl-CoA, FADH2, and NADH. [7] Acetyl-CoA is then used in the citric acid cycle while FADH2 and NADH are sent to the electron transport chain. [8]