Biology Regents Practice Exam

Which of the following is a role of proteins in living organisms?

1. Providing genetic information

2. Serving as enzymes to catalyze reactions

3. Storing genetic material

4. Transporting oxygen in the blood

The correct answer is: Serving as enzymes to catalyze reactions

Proteins play a crucial role in living organisms, and one of their key functions is serving as enzymes that catalyze biochemical reactions. Enzymes are specialized proteins that accelerate reactions by lowering the activation energy required, allowing vital metabolic processes to occur more efficiently and at lower temperatures than would otherwise be possible. This catalytic ability is essential for cellular function, enabling processes such as digestion, energy production, and DNA replication. While proteins contribute to other functions, such as transporting oxygen in the blood (as in hemoglobin), their role as enzymes is foundational to nearly all biological processes. Unlike genetic material, which is primarily the function of nucleic acids, and protein storage, which does not relate to the fundamental function of enzymes, the ability of proteins to catalyze reactions highlights their importance in the physiology of all living organisms.