What is the primary function of amino acids in biological systems?

Amino acids play a crucial role in biological systems primarily as the building blocks of proteins. Proteins are vital macromolecules that perform numerous functions within living organisms, including structural roles, acting as enzymes to facilitate biochemical reactions, and contributing to immune responses. Each protein is composed of a unique sequence of amino acids, which determine the protein's specific structure and function.

While amino acids can be involved in other processes within the body, such as contributing to the metabolic pathways that produce energy or being utilized in the synthesis of nucleic acids and other important biomolecules, their fundamental role lies in the synthesis of proteins. This function is essential to life, as proteins are involved in nearly every cellular function.