Which of the following is a major function of proteins composed of amino acids?

• A. Energy storage
• B. Genetic information storage
• C. Catalyzing biochemical reactions
• D. Structural support

Answer: (C)

The major function of proteins composed of amino acids is to catalyze biochemical reactions. Proteins, specifically enzymes (which are a type of protein), play a critical role in facilitating biochemical reactions by lowering the activation energy required for these reactions to occur. This catalytic activity allows metabolic processes to happen efficiently and at rates necessary for life.

Enzymes bind to substrates and convert them into products, enabling vital processes such as digestion, energy production, and DNA replication to proceed swiftly and effectively. Therefore, the catalysis of biochemical reactions is essential for maintaining the myriad of functions that sustain biological life, making it one of the central roles of proteins in living organisms.

While proteins do have structural support functions and can be involved in energy storage, those are not their primary roles compared to their catalytic functions. Additionally, genetic information storage is primarily associated with nucleic acids (DNA and RNA), not proteins.