What are the building blocks of proteins called?

The building blocks of proteins are known as amino acids. Amino acids are organic compounds that contain both an amine group and a carboxyl group, along with a distinctive side chain (R group) specific to each amino acid. There are 20 standard amino acids that combine in various sequences to form proteins through peptide bonds. The sequence and arrangement of these amino acids determine the structure and function of each protein in biological systems.

In contrast, carbohydrates serve as a source of energy and structural components in cells, lipids are involved in storing energy and cellular membrane structure, and nucleotides are the building blocks of nucleic acids like DNA and RNA. Each of these groups plays distinct roles in biological processes but does not serve as the building blocks for proteins. Understanding the fundamental role of amino acids in protein synthesis is crucial for studying biochemistry and molecular biology.