What role do enzymes play in the body?

• A. They act as catalysts to accelerate chemical reactions
• B. They provide energy for cellular processes
• C. They transport substances across cell membranes
• D. They regulate cell division and growth

Answer: (A)

Enzymes are biological catalysts that play a crucial role in facilitating and accelerating chemical reactions in the body without undergoing any permanent changes themselves. They function by lowering the activation energy required for a reaction to proceed, which significantly increases the reaction rate. This is essential for various physiological processes, including digestion, metabolism, and DNA replication, where timely interactions and conversions of substrates into products are necessary for maintaining life.

Other options reference roles that are not primarily associated with enzymes. Providing energy for cellular processes relates more to ATP and other energy carriers. Transporting substances across cell membranes involves other types of proteins, such as transporters and channels. Regulating cell division and growth is primarily influenced by signaling molecules and various regulatory proteins rather than by enzyme activity alone.