What are the building blocks of proteins that form in chains?

The building blocks of proteins are amino acids, which are organic compounds that combine to form proteins through a process called protein synthesis. Each amino acid consists of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a distinctive side chain (R group), which gives each amino acid its unique properties. During protein synthesis, amino acids are linked together in a specific sequence by peptide bonds, resulting in a polypeptide chain. These chains then fold into complex three-dimensional shapes to form functional proteins, playing vital roles in various biological processes, including enzyme activity, structural functions, and signaling pathways.

Understanding that amino acids are the fundamental units that create proteins clarifies their pivotal role in biochemistry and the overall functioning of living organisms. The other options represent different types of biological macromolecules: sugars are the building blocks of carbohydrates, fatty acids are components of lipids, and nucleotides serve as the building blocks of nucleic acids like DNA and RNA. Each of these plays essential but distinct roles within biological systems compared to the specific function of amino acids in protein formation.