Question 32:
The energy derived from noncovalent interactions between enzyme and substrate is called:
Answer: (C) Binding energy. This is the energy from noncovalent interactions between enzyme and substrate.
Option Explanations
Each option relates to enzyme kinetics, but only one matches the query precisely.
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(A) Bond energy: Energy to break/form covalent bonds in reactions; not specific to noncovalent enzyme-substrate links.
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(B) Activation energy: Minimum energy barrier for reaction; enzymes lower it, but it’s not “derived from” interactions.
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(C) Binding energy: Correct—free energy from noncovalent forces (H-bonds, van der Waals) stabilizing enzyme-substrate complex.
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(D) Entropy: Measure of disorder; binding often reduces it, unrelated to energy “derived” from interactions.
Introduction
Energy derived from noncovalent interactions enzyme substrate powers catalysis in biochemistry. For GATE Life Sciences, understanding this as binding energy clarifies enzyme mechanisms.
Binding Energy Defined
Binding energy arises from noncovalent forces like hydrogen bonds and electrostatics in the enzyme-substrate complex.
It lowers activation energy by stabilizing the transition state over ground state.
In life sciences, it’s key for specificity in reactions like glycolysis enzymes.
Role in Catalysis
Enzymes use binding energy to distort substrates or align them precisely.
This pays the entropic cost of association, accelerating rates up to 10^8-fold.
| Term | Source | Enzyme Function |
|---|---|---|
| Binding Energy | Noncovalent interactions | Stabilizes ES complex |
| Activation Energy | Energy barrier | Reduced by enzymes |
| Substrate Binding | Active site affinity | Forms ES → EP |
GATE MCQ Solved
Question 32: Energy from noncovalent interactions enzyme-substrate?
(A) Bond (B) Activation (C) Binding (D) Entropy
(C) matches definition; others confuse mechanisms.
