Glycine

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Glycine is a nonpolar amino acid. It is the simplest of the 20 natural amino acids; its side chain is a hydrogen atom.

Related Topics:
Nonpolar - Amino acid - Side chain - Hydrogen - Atom

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Because there is a second hydrogen atom at the α carbon, glycine is not optically active.

Related Topics:
Carbon - Optically active

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Since glycine has such a small side chain, it can fit into many places where no other amino acid can.

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For example, only glycine can be the internal amino acid of a collagen helix.

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Glycine is very evolutionarily stable at certain positions of some proteins (for example, in cytochrome c, myoglobin, and haemoglobin), because mutations that change it to an amino acid with a larger side chain could break the protein's structure.

Related Topics:
Protein - Cytochrome - Myoglobin - Haemoglobin

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Most proteins contain only small quantities of glycine. A notable exception is collagen, which is about one-third glycine.

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