Pyruvic acid + CoA + `NAD^(+) overset(A)(rarr) B+CO_(2)+NADH^(+)+H^(+)`
in the above given reaction of respiration what can be placed at the place of A and B respectively?

Options

A. Iron and Citric acid
B. Magnesium and Citric acid
C. Dehydrogenase and Acetyl CoA
D. Iron and Acetyl CoA

Answer

To solve the question, we need to identify what can be placed at the positions A and B in the reaction:

**Given Reaction:**
\[ \text{Pyruvic acid} + \text{CoA} + \text{NAD}^+ \overset{(A)}{\rightarrow} B + \text{CO}_2 + \text{NADH}^+ + \text{H}^+ \]

### Step-by-Step Solution:

1. **Identify the Reactants:**
- The reactants are Pyruvic acid, CoA (Coenzyme A), and NAD⁺ (Nicotinamide adenine dinucleotide).

2. **Understand the Process:**
- Pyruvic acid is produced from glycolysis and enters the mitochondria for further processing. In the mitochondria, it undergoes a process called oxidative decarboxylation.

3. **Determine the Enzyme Involved:**
- The enzyme that catalyzes the reaction of pyruvic acid with CoA and NAD⁺ is called **Pyruvate Dehydrogenase**. This enzyme facilitates the conversion of pyruvic acid into Acetyl CoA.

4. **Identify the Products:**
- During this reaction, pyruvic acid is decarboxylated (loses a carbon atom in the form of CO₂), and NAD⁺ is reduced to NADH. The remaining part of pyruvic acid combines with CoA to form Acetyl CoA.

5. **Assign A and B:**
- Therefore, at position A, we place **Pyruvate Dehydrogenase** (the enzyme), and at position B, we place **Acetyl CoA** (the product formed).

### Final Answer:
- A = **Pyruvate Dehydrogenase**
- B = **Acetyl CoA**