Subtopic: Fundamentals of Biomolecules, enzyme kinetics
Question Statement:
The pungency of mustard seeds is primarily due to secondary metabolites such as isothiocyanate
and nitrile. The pungency is usually felt only when the seeds are crushed. This is because of
Options:
(A) Ratio of unsaturated to saturated fatty acids would increase
(B) Ratio of unsaturated to saturated fatty acids would decrease
(C) Absolute amount of both fatty acids would increase keeping the ratio same
(D) Absolute amount of both fatty acids would remain unchanged
Official Answer Key:
B
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2014 Q.50)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **MCQ** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Systematic Conceptual & Option-by-Option Evaluation**:
- Problem Focus: *"The pungency of mustard seeds is primarily due to secondary metabolites such as isothiocyanate
and nitrile. The pungency is usually felt only when the seeds are crushed. This is because of..."*
- **Option (B) [CORRECT]**: *"the pungent chemicals are stored as inactive conjugates and compartmentalized from the
enzymes that convert them into active chemicals"*
- Validated by canonical biochemistry/biotechnology literature. Specifically matches the molecular mechanism, kinetic model, or empirical finding required.
- **Option (A) [INCORRECT]**: *"the coat of the intact seeds blocks the pungent volatiles from being releas"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (C) [INCORRECT]**: *"the pungent chemicals are formed only after the reaction with atmospheric o"* does not satisfy the precise boundary conditions or molecular specificity.
- **Option (D) [INCORRECT]**: *"the pungent chemicals are formed only after the reaction with atmospheric c"* does not satisfy the precise boundary conditions or molecular specificity.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **B**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.66 marks).
Practice This in Real CBT Exam Interface
Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.