Which of the Following Amino Acids is Not Optically Active

Question

Which of the following amino acids is not optically active?
A) alanine
B) glycine
C) tryptophan
D) none, all of these are optically active

Accepted Answer

Glycine is not optically active because it has a hydrogen atom as its side chain, which does not have a chiral center. All other amino acids have chiral centers in their side chains, making them optically active.