Which of the following statements is true regarding proteins?

Proteins play a crucial role in biological processes, and one of their main functions is acting as enzymes that facilitate and regulate chemical reactions within the body. Enzymes are specialized proteins that speed up these reactions, making it possible for the cell to perform necessary functions efficiently.

Proteins also serve various other roles, such as structural support, transport of molecules, and immune responses. The functionality of enzymes is a direct result of their specific structures, which allow them to interact with other molecules selectively. This characteristic of proteins underscores their importance in controlling cell functions and overall metabolic processes.

The other statements do not accurately reflect the primary functions of proteins. Proteins do not store genetic information—that function is primarily the role of nucleic acids like DNA and RNA. While proteins can provide energy, they are not primarily energy storage molecules; that role is typically fulfilled by carbohydrates and fats. Lastly, although some proteins can be insoluble in water, many are actually soluble and function effectively in aqueous environments, which is vital for their biological roles. Thus, the assertion regarding proteins acting as enzymes and controlling cell functions is clearly supported by their established biochemical roles.