Final answer:
Amino acids in proteins differ in their side chains or R groups, which provide unique properties to each amino acid and affect the protein's structure and function.
Step-by-step explanation:
Amino acids in proteins differ in their side chains or R groups, which provide unique properties to each amino acid and affect the protein's structure and function. The amino acids present in proteins differ in their side chains, which are also known as R groups. These R groups can vary widely, from a single hydrogen atom to complex carbon chains with different functional groups.
The variation in side chains provides each amino acid with unique properties, such as size, shape, solubility, and ionization, which in turn affect the overall structure and function of a protein. This diversity in side chains is critical as it allows proteins to adopt a vast array of structures and execute numerous functions essential for life.