Biology Regents Practice Exam

Proteins are essential macromolecules made up of smaller units called amino acids. Each amino acid consists of a basic amino group, an acidic carboxyl group, and a unique side chain or R group that determines the specific characteristics of that amino acid. There are 20 different amino acids that combine in various sequences to form proteins.

Proteins can have diverse functions, such as acting as enzymes, transporting molecules, providing structural support in cells and tissues, and playing roles in immune response. The unique sequence of amino acids in a protein ultimately determines its structure and function, making them vital for biological processes in all living organisms.

In contrast, fatty acids are the building blocks of lipids, nucleotides make up nucleic acids like DNA and RNA, and monosaccharides are the simplest forms of carbohydrates, serving as the building blocks for more complex sugars. Each of these components plays a distinct role in biological systems, but amino acids are uniquely responsible for the formation of proteins.