α carbon

Definition

The α carbon is the central carbon atom in an amino acid to which the amino group, carboxyl group, and R group (side chain) are attached. It plays a crucial role in the structure and function of proteins.

5 Must Know Facts For Your Next Test

1. The α carbon is chiral in all amino acids except glycine, leading to L- and D-isomers.
2. It is the backbone of protein secondary structures like α-helices and β-sheets.
3. The rotation around the bonds involving the α carbon affects protein folding and stability.
4. In peptide bonds, the α carbon connects adjacent amino acids via their carboxyl and amino groups.
5. The properties of the R group attached to the α carbon determine the characteristics and function of each amino acid.

Review Questions

• Why is the α carbon considered chiral in most amino acids?
• How does the α carbon contribute to protein secondary structures?
• What role does the α carbon play in peptide bond formation?

Related terms

Peptide Bond: A covalent bond that links amino acids together in a protein.

R Group: The side chain attached to an amino acid's α carbon, which determines its properties.

Chiral Center: An atom with four different groups attached, leading to non-superimposable mirror images.