Out of 36 ATP molecules produced per glucose molecule during respiration

Options

A. 2 are produced outside glycolysis and 34 during respiratory chain
B. 2 are produced outside mitochondria and 34 inside mitochondria
C. 2 during glycolysis and 34 during Krebs' cycle
D. all are formed inside mitochondria

Explanation

To solve the question regarding the production of ATP during respiration, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding Glycolysis**:
- Glycolysis is the first step in the respiration process where glucose is broken down into pyruvate.
- During glycolysis, a total of **2 ATP molecules** are produced through substrate-level phosphorylation.

2. **NADH Production in Glycolysis**:
- In addition to the ATP produced, glycolysis also generates **2 NADH molecules**.
- Each NADH can be converted into **3 ATP** during oxidative phosphorylation in the electron transport chain. Therefore, from 2 NADH, we can expect **6 ATP** (2 NADH x 3 ATP/NADH).

3. **Total ATP from Glycolysis**:
- Combining the ATP produced directly in glycolysis and the ATP from NADH, we have:
- **2 ATP (from glycolysis) + 6 ATP (from NADH) = 8 ATP**.

4. **Krebs Cycle (Citric Acid Cycle)**:
- The pyruvate produced in glycolysis enters the Krebs cycle.
- Each glucose molecule results in the production of **30 ATP** from the Krebs cycle and oxidative phosphorylation.
- This includes **2 ATP from substrate-level phosphorylation** in the Krebs cycle and **28 ATP from the electron transport chain**.

5. **Total ATP from the Entire Process**:
- Adding the ATP produced from glycolysis and the Krebs cycle:
- **8 ATP (from glycolysis) + 30 ATP (from Krebs cycle) = 36 ATP**.

6. **Location of ATP Production**:
- The **2 ATP from glycolysis** are produced in the **cytoplasm** (outside the mitochondria).
- The **34 ATP** (30 from Krebs cycle and 6 from glycolysis via NADH) are produced in the **mitochondria** (inside).

### Conclusion:
The correct answer to the question is that **2 ATP are produced outside the mitochondria (during glycolysis), and 34 ATP are produced inside the mitochondria (28 from Krebs cycle and 6 from glycolysis via NADH)**.