acyl

(noun)

Any of class of organic radicals, RCO-, formed by the removal of a hydroxyl group from a carboxylic acid.

Related Terms

Examples of acyl in the following topics:

  • Lipid Metabolism

    • Activation: Before fatty acids can be metabolized, they must be "activated. " This activation step involves the addition of a coenzyme A (CoA) molecule to the end of a long-chain fatty acid, after which the activated fatty acid (fatty acyl-CoA) enters the β-oxidation pathway.
    • Oxidation: The initial step of β-oxidation is catalyzed by acyl-CoA dehydrogenase, which oxidizes the fatty acyl-CoA molecule to yield enoyl-CoA.
    • As a result of this process, a trans double bond is introduced into the acyl chain.
    • Cleavage: A thiolase then cleaves off acetyl-CoA from the oxidized molecule, which also yields an acyl-CoA that is two carbons shorter than the original molecule that entered the β-oxidation pathway.

  • Organic Acid Metabolism

    • This process requires the β-oxidation pathway, a cyclic process that catalyzes the sequential shortening of fatty acid acyl chains to the final product, acetyl-CoA.
    • Fatty acid chains are converted to enoyl-CoA (catalyzed by acyl-CoA dehydrogenase).

  • Lipid Biosynthesis

    • The acyl chains in the fatty acids are extended by a cycle of reactions that add the acetyl group, reduce it to an alcohol, dehydrate it to an alkene group and then reduce it again to an alkane group.
    • The synthesis of unsaturated fatty acids involves a desaturation reaction, whereby a double bond is introduced into the fatty acyl chain.
    • Triglyceride synthesis takes place in the endoplasmic reticulum by metabolic pathways in which acyl groups in fatty acyl-CoAs are transferred to the hydroxyl groups of glycerol-3-phosphate and diacylglycerol.

  • Nonribosomal Peptide Antibiotics

    • Nonribosomal peptides often have a cyclic and/or branched structures, can contain non-proteinogenic amino acids including D-amino acids, carry modifications like N-methyl and N-formyl groups, or are glycosylated, acylated, halogenated, or hydroxylated.

  • Cofactors and Energy Transitions

    • Many organic cofactors also contain a nucleotide, such as the electron carriers NAD and FAD, and coenzyme A, which carries acyl groups.

  • Quorum Sensing

    • Common classes of signaling molecules are oligopeptides in Gram-positive bacteria, N-Acyl Homoserine Lactones (AHL) in Gram-negative bacteria, and a family of autoinducers known as autoinducer-2 (AI-2) in both Gram-negative and Gram-positive bacteria.