How many protons will be pump in outer chamber of mitochondria if pyruvic acid is competely oxidised?

Options

A. 28
B. 30
C. 32
D. 26

Answer

To determine how many protons will be pumped into the outer chamber of mitochondria when pyruvic acid is completely oxidized, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Aerobic Respiration**:
- Aerobic respiration involves the complete oxidation of glucose to produce energy. The process begins with glycolysis, where glucose is broken down into two molecules of pyruvate.

2. **Conversion of Pyruvate**:
- Each pyruvate (3-carbon compound) is converted into acetyl coenzyme A (2-carbon compound) before entering the TCA (Krebs) cycle. Since one glucose molecule produces two pyruvate molecules, we will consider the oxidation of two pyruvate molecules.

3. **TCA Cycle**:
- During the TCA cycle, each acetyl CoA will go through a series of reactions, resulting in the production of NADH and FADH2.
- For each pyruvate, the TCA cycle produces:
- 3 NADH
- 1 FADH2
- Therefore, for two pyruvate molecules, we get:
- 2 pyruvate x 3 NADH = 6 NADH
- 2 pyruvate x 1 FADH2 = 2 FADH2

4. **Electron Transport Chain (ETC)**:
- The NADH and FADH2 produced in the TCA cycle then enter the electron transport chain (ETC), where they donate electrons.
- Each NADH can pump 3 protons (H+) across the mitochondrial membrane into the outer chamber.
- Each FADH2 can pump 2 protons (H+) across the membrane.

5. **Calculate Protons Pumped**:
- From 6 NADH:
- 6 NADH x 3 protons = 18 protons
- From 2 FADH2:
- 2 FADH2 x 2 protons = 4 protons
- Total protons pumped = 18 protons + 4 protons = 22 protons.

### Final Answer:
When pyruvic acid is completely oxidized, a total of **22 protons** will be pumped into the outer chamber of mitochondria.

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