Chemistry · Chemistry of Life
Work through this past-paper style MCQ, then read the full explanation. Practice more chemistry questions on mMCQ with adaptive practice and topic analytics.
Indicate the cyclic amino acid from the following
- A
Cysteine
- B
Serine
- C
Haloamine
- D
Proline
Haloamine is not an amino acid but is rather a class of organic compounds containing an amine and halogen group. The structures of Cysteine, serine, and proline are shown below. Only Proline contains a ring in its structure and hence is cyclic.
Cystine is not a cyclic amino acid. It is a dimer of the amino acid cysteine, formed by the oxidation of two cysteine residues, resulting in a covalent linkage between the sulfur atoms of two cysteine molecules. It forms disulfide bonds in proteins, contributing to their tertiary and quaternary structures.
Serine is not a cyclic amino acid either. It is a nonpolar amino acid with a hydroxyl group (-OH) as its side chain. It plays important roles in protein structure and function, often participating in hydrogen bonding and enzymatic reactions.
Halomine" doesn't appear to be a commonly known amino acid. It's possible you meant "histidine," which contains an imidazole side chain, but histidine is not cyclic in the same sense as proline.
Proline is the cyclic amino acid in the list. It has a unique structure where its side chain forms a cyclic structure with the amino group, creating a pyrrolidine ring. This structural feature imparts rigidity to protein structures and is often found in turns and loops in proteins. Proline is also known as an imino acid due to its distinctive structure
Tagged under Chemistry · Chemistry of Life · 2014