Kaplan Nursing Entrance Practice Exam

What role do enzymes play in chemical reactions involving substrates?

1. They slow down reactions

2. They speed up chemical reactions

3. They create new substrates

4. They neutralize substrates

The correct answer is: They speed up chemical reactions

Enzymes play a crucial role in biochemical reactions by acting as catalysts that significantly speed up the rate of chemical reactions involving substrates. They achieve this by lowering the activation energy needed for a reaction to occur, which facilitates the conversion of substrates into products more efficiently and swiftly. Enzymes are highly specific, meaning that each enzyme typically catalyzes a particular reaction or set of reactions, allowing for precise control of metabolic pathways. This catalytic activity is fundamental for sustaining life, as many biological reactions would occur too slowly without the presence of enzymes, preventing the proper functioning of cellular processes. Their ability to increase reaction rates is critical in processes such as digestion, energy production, and biosynthesis, where timing is essential for cellular health and overall organism viability.