What is the role of amino acids in biological systems?

Amino acids play a critical role in biological systems, primarily because they are the building blocks of proteins. Proteins are essential macromolecules that perform a myriad of functions in living organisms, including acting as enzymes, structural components, transporters, antibodies, and hormones. The sequence and composition of amino acids in a protein determine its unique structure and function, making them integral to metabolism, growth, and overall cellular function.

While amino acids can also have other roles—such as being a source of energy or acting as signaling molecules—these functions are secondary to their primary role in protein synthesis. The process of protein synthesis involves linking amino acids in specific sequences dictated by messenger RNA, which is a fundamental aspect of gene expression and cellular activity.