Which statement best describes a key property of enzymes regarding their use in repeated catalytic cycles?

• A. An enzyme can be reused only if it binds covalently to the substrate during catalysis.
• B. An enzyme can catalyze only one substrate molecule and is irreversibly altered after a single reaction cycle.
• C. An enzyme can be reused to catalyze reactions with new substrate molecules because it is not permanently consumed during the reaction.
• D. An enzyme must be resynthesized after each reaction because it is converted into product along with the substrate.

Answer: (C)

Verified step by step guidance

1. Understand the role of enzymes as biological catalysts that speed up chemical reactions without being consumed in the process.
2. Recall that enzymes bind to substrates to form an enzyme-substrate complex, facilitating the conversion of substrates into products.
3. Recognize that during catalysis, enzymes undergo temporary changes but return to their original state after the reaction, allowing them to participate in multiple reaction cycles.
4. Note that enzymes do not form permanent covalent bonds with substrates that would prevent their reuse; instead, any binding is typically reversible.
5. Conclude that the key property of enzymes is their ability to be reused repeatedly to catalyze reactions with new substrate molecules because they are not permanently altered or consumed.