What are the fundamental building blocks of proteins?

Amino acids are indeed the fundamental building blocks of proteins. Proteins are large, complex molecules that play many critical roles in the body, including acting as enzymes, hormones, and structural components. Each protein is composed of a chain of amino acids, which are linked together by peptide bonds in a specific sequence determined by the organism's DNA.

There are twenty different amino acids that can be combined in various sequences to form a vast array of proteins, each with unique functions and properties. The sequence and arrangement of amino acids dictate the protein's structure and function; even a small change in the amino acid sequence can significantly affect the protein’s characteristics.

Other options such as fatty acids, carbohydrates, and nucleotides do not serve as building blocks for proteins. Fatty acids are the building blocks of lipids, carbohydrates consist of sugar molecules that provide energy and structural support, and nucleotides are the components of nucleic acids like DNA and RNA. Each of these biomolecules has distinct roles in biological systems, but they do not contribute to the structure of proteins.