What is an enzyme's turnover number?

What is an enzyme's turnover number?

• A. The rate of enzyme synthesis in cells
• B. The number of active sites on the enzyme
• C. The maximum substrate molecules converted per unit time
• D. The total time an enzyme remains active

Answer: (C)

An enzyme's turnover number, often represented as k_cat, refers to the maximum number of substrate molecules that can be converted into product by a single enzyme molecule in a given unit of time, typically measured under optimal conditions for the enzyme. This measurement reflects how efficiently the enzyme catalyzes a reaction once it is saturated with substrate, providing valuable insight into the enzyme's catalytic capabilities. In contrast, the other options do not accurately describe the concept of turnover number. For instance, the rate of enzyme synthesis in cells relates to enzyme production rather than the efficiency of the enzyme. The number of active sites on the enzyme does not provide a measure of activity but rather indicates the enzyme's structural characteristics. Lastly, the total time an enzyme remains active is unrelated to its turnover number, as it does not capture the efficiency of the conversion process over time. Overall, the turnover number is a key parameter in understanding the performance of enzymes as biological catalysts.

An enzyme's turnover number, often represented as k_cat, refers to the maximum number of substrate molecules that can be converted into product by a single enzyme molecule in a given unit of time, typically measured under optimal conditions for the enzyme. This measurement reflects how efficiently the enzyme catalyzes a reaction once it is saturated with substrate, providing valuable insight into the enzyme's catalytic capabilities.

In contrast, the other options do not accurately describe the concept of turnover number. For instance, the rate of enzyme synthesis in cells relates to enzyme production rather than the efficiency of the enzyme. The number of active sites on the enzyme does not provide a measure of activity but rather indicates the enzyme's structural characteristics. Lastly, the total time an enzyme remains active is unrelated to its turnover number, as it does not capture the efficiency of the conversion process over time. Overall, the turnover number is a key parameter in understanding the performance of enzymes as biological catalysts.