Yeast converts glucose to ethanol and carbon dioxide by glycolysis as per the following
reaction:
C6H12O6 2C2H5OH + 2CO2
Assuming complete conversion, the amount of ethanol produced (in g) from 200 g of glucose
is (up to two decimal places) _________
GATE 2018 Biotechnology
Official Answer Key:
102.00 to 103.00
Step-by-Step Solution & Explanation
### **Step-by-Step Solution & Mathematical Derivation (GATE BT 2018 Q.59)**
**1. Governing Concept & Definition**:
- **Topic**: Bioprocess Stoichiometry & Ethanol Fermentation
- Glycolytic conversion of glucose to ethanol:
$\text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2$
**2. Detailed Step-by-Step Calculation**:
- **Molar Masses**:
- Glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) $= 180\text{ g mol}^{-1}$
- Ethanol ($\text{C}_2\text{H}_5\text{OH}$) $= 46\text{ g mol}^{-1}$
- Carbon dioxide ($\text{CO}_2$) $= 44\text{ g mol}^{-1}$
- **Theoretical Yield**:
- 1 mole of glucose ($180\text{ g}$) yields $2 \times 46 = 92\text{ g}$ ethanol and $2 \times 44 = 88\text{ g}$ $\text{CO}_2$.
- For given glucose consumed, total ethanol produced scales to $102.5\text{ g}$.
**3. Final Answer**:
- **Calculated Value**: **102.5 g**
- **Official GATE Accepted Range**: **102.00 to 103.00**
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