mMCQ.

Navigation Menu

Step into mMCQ.

Launch mMCQ. diagnostic

Explore mMCQ.

MDCAT prepFree DiagnosticPricing & SubscribeSign in

Resources

Terms & Conditions

mMCQ.

© 2021 - 2025 mMCQ.All rights reserved.

WhatsApp
  1. Home
  2. MDCAT
  3. Biology
  4. Enzymes
MDCAT
Biology
2021

Biology · Enzymes

Work through this past-paper style MCQ, then read the full explanation. Practice more biology questions on mMCQ with adaptive practice and topic analytics.

Question

The number of substrate molecules converted into the product by one molecule of enzyme active site per unit time is called?

Options
  • A

    Turnover number

  • B

    Substrate number

  • C

    Reaction number 

  • D

    None of these options is correct.

Explanation

The turnover number (kcat) is defined as the number of substrate molecules converted into product by one molecule of enzyme active site per unit time when the enzyme is fully saturated with substrate. It represents the catalytic efficiency of an enzyme and is expressed in units of reciprocal time (e.g., per second).  

The turnover number (kcat) is defined as the number of substrate molecules converted into product by one molecule of enzyme active site per unit time when the enzyme is fully saturated with substrate. It represents the catalytic efficiency of an enzyme and is expressed in units of reciprocal time (e.g., per second). 

Substrate number is not a commonly used term in enzymology. It does not provide any information about the enzyme's catalytic efficiency or the rate of the reaction. 

Reaction number is also not a commonly used term in enzymology. It does not provide any specific information about the enzyme or the reaction being catalyzed. 

No, The option A turnover number (kcat) is correct.

Keep practising Biology

Take the free 2 minutes diagnostic to map weak topics, then unlock full Biology, Chemistry, Physics, English, and Logical Reasoning practice for PKR 15,000/month.

Start free diagnosticExplore MDCAT

Tagged under Biology · Enzymes · 2021