This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Which amino acid is acidic? \nSelect and explain. \nA. Aspartic acid, B. Valine, C. Leucine, D. Aspartate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Aspartic acidBased in variable side chain, amino acid can be classified into: Aliphatic amino acid and Aromatic amino acid.Aliphatic amino acidAromatic amino acidIt is further classified into several subtypes:* Simple AA: Glycine, Alanine* Branched chain AA: Leucine, Isoleucine, Valine* Sulphur containing: Cysteine, Methionine* With-OH group: Serine, Threonine* With amide group: Asparagine, Glutamine* Acidic AA: Aspartic acid, Glutamic acid* Basic AA: Arginine, Lysine* Histidine* Tyrosine* Tryptophan* Phenylalanine* Basic amino acid: Histidine, Arginine, Lysine (Histidine is also basic in nature, but it is aromatic)* -OH containing AA: Threonine, Serine, Tyrosine* Most basic amino acid: Arginine', 'role': 'assistant'}]