methyl group

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methyl group

A chemist draws a methyl group on the whiteboard.

Definition

Noun: - A univalent alkyl radical: The methyl group is a fundamental chemical unit with the formula CH₃⁻. It consists of one carbon atom bonded to three hydrogen atoms and has one free valence, allowing it to attach to other atoms or molecules. It is derived from methane (CH₄) by the removal of one hydrogen atom.

Usage and Examples
  • As a constituent part of larger molecules:
    • In organic chemistry, a methyl group is often added to or removed from compounds in reactions called methylation and demethylation.
    • The addition of a methyl group to the DNA molecule can affect gene expression.
  • Describing molecular structure:
    • The compound toluene contains a methyl group attached to a benzene ring.
    • The difference between ethanol and methanol is that methanol has only a methyl group bonded to a hydroxyl group.
Advanced Usage
  • In biochemistry and genetics: Methyl groups play a critical role in epigenetic regulation, where they modify DNA and histones.
    • Hypermethylation of a gene promoter, involving many methyl groups, can silence that gene.
  • As a reference in spectroscopy: The presence of methyl groups in a molecule gives characteristic signals in techniques like NMR (Nuclear Magnetic Resonance).
    • The NMR spectrum showed a distinct peak for the protons in the methyl group.
Variants and Related Words
  • Methylate (verb): To introduce a methyl group into a compound.
    • Scientists methylate the compound to study its new properties.
  • Methylation (noun): The chemical process of adding a methyl group to a substrate.
    • DNA methylation is a common epigenetic modification.
  • Methylated (adjective): Describing a compound that has had a methyl group added.
    • Methylated spirits are ethanol denatured by the addition of methanol.
Synonyms
  • Methyl radical: A less common but technically accurate synonym.
  • CH₃ group: A formulaic synonym used in chemical notation.
Related Phrases and Concepts
  • Methyl donor: A molecule, such as S-adenosyl methionine (SAM), that can transfer a methyl group to another molecule.
    • SAM serves as the primary methyl donor in biological systems.
  • Methyl terminus: Refers to the end of a hydrocarbon chain that is a methyl group.
    • The fatty acid has a methyl terminus at one end and a carboxyl group at the other.
methyl group

A chemist draws a methyl group on the whiteboard.

Noun
  1. the univalent radical CH3- derived from methane

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