What is not a function of proteins?

Proteins serve a multitude of functions within biological systems, and while they are involved in various processes, generating energy for the cell is not one of their primary functions. Instead, energy generation is primarily attributed to metabolic processes that involve carbohydrates, fats, and other organic molecules rather than proteins themselves.

Proteins are crucial for acting as enzymes, which catalyze biochemical reactions and facilitate metabolic processes without being consumed in the reaction. Additionally, they play a pivotal role in the transportation of solutes across cell membranes, functioning as channels or carriers to help move substances into and out of cells. Lastly, proteins can serve in regulatory functions, including being involved in signaling pathways and acting as pigments that help absorb light, contributing to processes such as photosynthesis.

Therefore, among the listed options, the generation of energy is more accurately associated with bioenergetics involving carbohydrates and lipids rather than being a direct function of proteins.