This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Amino acid which lacks chirality is 
Select and explain. 
A. Lysine, B. Leucine, C. Histidine, D. Glycine
D: Glycine
Answer: D: Glycine 
Explanation: The α-carbon of amino acids has four different groups attached to it and so is a chiral or asymmetric carbon.
The only amino acid which does not have four different groups attached to α-carbon is glycine, i.e. glycine does not have chiral carbon or chirality.