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
Acidic propey to a-carbon of amino acid is due to 
Select and explain. 
A. Carboxyl group, B. Amino group, C. Hydrogen atom, D. None
A: Carboxyl group
Answer: A: Carboxyl group 
Explanation: Ans. is 'a' i.e., Carboxyl groupThe acid base propeies of amino acids depend on the amino and carboxyl groups attached to the a-carbon.The carboxyl (-COOH) group of an amino acid can donate protein (H') and behave as an acid forming a negatively charged anion (C00-).Amino group (-NH) can accept proton (H') and behave as a base, forming positively charged cation (NH3').