How do proteins with different functions in the body arise?

Proteins with different functions in the body arise primarily from linking together different sequences of amino acids. The unique sequence of amino acids in a protein determines its specific structure and function. Each protein is made up of a specific combination of the 20 different amino acids, and the order in which these amino acids are arranged (the primary structure) influences the protein's overall shape (the secondary and tertiary structures), which is crucial for its biological activity.

The diversity of protein functions stems from the vast number of possible combinations and arrangements of these amino acids, allowing for a wide range of protein structures and consequently a variety of functions in biological processes. Each protein's specific sequence is encoded by genes, which ultimately dictate how proteins are synthesized in cells, contributing to the vast array of tasks performed by proteins in the body.

While post-translational modifications can alter the function of proteins, the fundamental basis for the diversity of protein functionality lies in the different sequences of amino acids used in their formation.