AP BIOLOGY

Detailed explanation-1: -Amino acids are the smallest and basic structural units of proteins. Amino acids of same or different types combine together to form a polypeptide chain and many polypeptide chains, in turn, join to form a complex structure called protein.

Detailed explanation-2: -The chemistry of amino acid side chains is critical to protein structure because these side chains can bond with one another to hold a length of protein in a certain shape or conformation. Charged amino acid side chains can form ionic bonds, and polar amino acids are capable of forming hydrogen bonds.

Detailed explanation-3: -In the human body, there are 20 amino acids that function as building blocks of proteins. Nine of these amino acids are considered essential-they must be consumed in the diet-while five are considered nonessential in that they can be made by the human body.

Detailed explanation-4: -The basic structure of an amino acid is a central carbon atom bonded to an amino group (NH2), a carboxyl group (COOOH), and a hydrogen atom.

Detailed explanation-5: -Scientists have identified approximately 500 naturally occurring amino acids, of which only 20 are used to make proteins in the human body, earning them the sobriquet proteinogenic amino acids. These 20 amino acids link together in varying combinations to form different types of protein.