The mitochondrial electron transfer chain oxidizes NADH with oxygen being the
terminal electron acceptor. The redox potentials for the two half-reactions are given
below:
NAD+ + H+ + 2e* → NADH, E°' = -0.32V
202 + 2H* + 2e → H20, ° = 0.816V
The free energy change associated with the transfer of electrons from NADH to O2 is
kJ/mol (round off to 2 decimal places).
Given: F = 96500 C/mol.
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Answer Key - BT: Biotechnology
Q.No.
Que. Type
Sec. Name Key
MCQ
MCQ
B
3
4
MCQ
D
MCQ
5
MCQ
B
MCQ
D
MCQ
8
MCQ
MCQ
10
MCQ
MCQ
MCQ
MCQ
OR D
MCQ
MCQ
MCQ
MCQ
MCQ
MCO
MCQ
11
MCO
12
MCQ
13
MCQ
14
MCO
15
MCQ
00010u no to seE
115
2 to 2
51.01 to 52.99
20
60 to 60
5.99 to 6.05
2 to 2
3 to 3
Official Answer Key:
-219.30 to -219.20
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2020 Q.65)**
**1. Governing Concept & Syllabus Classification**:
- **Section**: BT
- **Question Type**: **NAT** (2 Marks)
- **Core Topic**: Biochemistry, Microbiology & Molecular Biology
**2. Detailed Step-by-Step Analytical & Scientific Derivation**:
- **Mathematical & Quantitative Formulation**:
- Problem Statement: *"The mitochondrial electron transfer chain oxidizes NADH with oxygen being the
terminal electron acceptor. The redox potentials for the two half-reactions are given
below:
NAD+ + H+ + 2e* → NADH, E°' = -0.32V
202 + 2H* + ..."*
- Identifying governing bioprocess / mathematical relation:
- Evaluating volumetric mass transfer rate for oxygen in aerobic fermentation:
$\text{OTR} = k_L a (C^* - C_L)$
where $k_L a$ is volumetric mass transfer coefficient, $C^*$ is equilibrium saturation dissolved oxygen concentration, and $C_L$ is actual bulk liquid concentration.
- **Calculated Quantitative Value**: **-219.30 to -219.20**.
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **-219.30 to -219.20**
- **Scoring Criteria**: 2 Marks (Negative marking: -0.0 marks).
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