Which statement about amino acids is true?
A) Most common natural amino acids in proteins are L-amino acids.
B) All naturally occurring amino acids in proteins are chiral.
C) Most naturally occurring amino acids in proteins are D-amino acids.
D) Naturally occurring amino acids in proteins occur as a mixture of enantiomers.

Question

Quizplus · Accepted Answer

The most common natural amino acids in proteins are L-amino acids, which have the amino group and carboxyl group on opposite sides of the central carbon atom.

Answer: B
 All naturally occurring amino acids in proteins are chiral, meaning they exist in two mirror-image forms (enantiomers).

Answer: D
 Naturally occurring amino acids in proteins occur as a mixture of enantiomers, typically with only the L-form being used in protein synthesis. Very few proteins contain D-amino acids, and they usually have specialized functions.

Which Statement About Amino Acids Is True