Summarize what makes amino acids chemically unique and categorize the 20 amino acids commonly found in proteins on the basis of their chemical properties.
A) Amino acids are unique due to their varied side chains and functional groups. Categorization based on chemical properties includes acidic, basic, polar, and nonpolar.
B) Amino acids are identical in structure but differ in molecular weight. Categories include aliphatic, aromatic, hydrophilic, and hydrophobic.
C) Amino acids vary in their peptide bond formation abilities. Categories include essential, nonessential, acidic, and basic.
D) Amino acids are characterized by their identical R-groups and peptide backbone. Categories include primary, secondary, tertiary, and quaternary.
