Insight :Amino acids are organic molecules that have both an amine and a carboxyl functional group, as well as a unique side chain.

Insight :There are 20 different amino acids that are commonly found in proteins, and they can be linked together by peptide bonds to form polypeptides.

Insight :Nine of the 20 amino acids are essential, meaning they cannot be synthesized by the human body and must be obtained from food sources.