# methyl

/ˈmɛθəɫ/ (US) · /mˈiːθaɪl/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/methyl
Updated: 2026-05-07

## Definition

a small group of atoms made of one carbon and three hydrogen atoms. It is a basic building block in chemistry that attaches to other molecules.

For teachers: an alkyl radical derived from methane, consisting of one carbon atom covalently bonded to three hydrogen atoms. Often functions as a functional group within larger organic molecules.

## Examples

- The scientist added a methyl group to the compound.
- In biology, adding a methyl group to DNA can change how genes are expressed without altering the genetic code itself.
- The synthesis of this specific hormone requires the transfer of a methyl group from a donor molecule, a process essential for maintaining metabolic balance within the cell.

## Usage notes

- Often used as a modifier before another noun, such as 'methyl group' or 'methyl alcohol'.

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