What are the building blocks of proteins called?

Amino acids are the fundamental units that compose proteins, serving as their building blocks. Each protein is made up of a specific sequence of amino acids, which determines the protein's structure and function. There are 20 different amino acids that can be combined in various ways to create a vast array of proteins, reflecting the diversity of roles proteins play in biological systems, including catalyzing reactions (as enzymes), providing structural support, and facilitating transport within cells.

Understanding protein structure begins with comprehending how amino acids link together through peptide bonds, forming polypeptides that eventually fold into functional three-dimensional shapes. This detailed knowledge of amino acids is essential for grasping topics in biochemistry, molecular biology, and genetics. Other options listed, such as fatty acids, sugars, and nucleotides, refer to different types of biological molecules, each with distinct roles that do not involve the direct building of proteins.