acet

Acet is a combining form used in chemistry and biochemistry to denote the acetyl group or related derivatives. The term is derived from acetyl and acetic, which in turn come from Latin acetum, meaning vinegar. In systematic nomenclature, the prefix acet- indicates a two-carbon acyl substituent with a carbonyl group, represented conceptually as CH3-CO-.

The acetyl group is encountered in a wide range of compounds, including acetates (esters of acetic acid), acetamides (amide derivatives), and various anhydrides and esters. In chemical reactions, acetylation introduces the acetyl group into a substrate, often using reagents such as acetyl chloride (CH3COCl) or acetic anhydride [(CH3CO)2O].

In biology, acetyl transfer is a common modification carried out by acetyltransferase enzymes, transferring the acetyl group from donors such as acetyl-CoA to substrates like proteins or small molecules. Acetyl-CoA is a central metabolic intermediate that donates two-carbon acetyl units in pathways such as the citric acid cycle and lipid synthesis, linking carbohydrate, lipid, and energy metabolism.

Biological regulation also involves acetylation of proteins, notably histones. Histone acetylation, mediated by histone acetyltransferases and removed by deacetylases, influences chromatin structure and gene expression.

In organic synthesis, the acetyl group is frequently used as a protective group for amines and alcohols (the acetyl or Ac protection). The prefix acet- appears in many related terms, including acetyl, acetate, and acetic acid.

See also: Acetyl, Acetate, Acetic acid, Acetyl-CoA.