Methyl group

In chemistry, methyl refers to a group of atoms with the formula CH₃ - one carbon atom with chemical bonds to three hydrogen atoms. It is a functional group in organic chemistry and ligand in organometallic chemistry. Methyl is the simplest alkyl group.^[1]

Different ways of representing a methyl group (highlighted in blue)

In genetics

Methyl groups added to cytosine are the basis of epigenetics. They change the way genes act, and so explain how (for example) identical twins may turn out differently later in life. Or, they help understand how a mother's nutrition may have long-lasting effects on her offspring.^[2]