Acetylation vs. Methylation — What's the Difference?

Acetylation (or in IUPAC nomenclature ethanoylation) is an organic esterification reaction with acetic acid. It introduces an acetyl functional group into a chemical compound.

In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom.

To bring an acetyl group into (an organic molecule).

An alkylation process involving addition of, or substitution by, a methyl group.

(organic chemistry) The reaction of a substance with acetic acid or one of its derivatives; the introduction of one or more acetyl groups into a substance.

The process of treating something with methyl alcohol.

The process of introducing an acetyl group into a compound;

(chemistry) The addition of a methyl group to a molecule.

(genetics) The addition of a methyl group to cytosine and adenine residues in DNA that leads to the epigenetic modification of DNA and the reduction of gene expression and protein production.