Question: What is one of the amino acids used in the biosynthesis of proteins, that is in a synthetic peptide consisting of eight amino acids?
Sentence (from "Histidine"): It contains an α-amino group (which is in the protonated –NH form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a positively charged amino acid at physiological pH. Initially thought essential only for infants, longer-term studies have shown it is essential for adults also.
Relevant evidence: No