Question

The respiratory pathway common to erythrocyte and leucocyte is

• A. oxidation of pyruvate to acetyl-CoA
• B. oxidation of acetyl-CoA
• C. release of ATP by electron transport-linked phosphorylation
• D. substrate level phosphorylation

Hint:

RBCs are "mitochondria-free" to ensure they don't consume the oxygen they are supposed to transport!

Answer 1

The Correct Option is B

Step 1: Concept
Respiration involves the breakdown of glucose to release energy. Erythrocytes (RBCs) lack mitochondria, while leucocytes (WBCs) contain them.

Step 2: Analysis
Because RBCs lack mitochondria, they cannot perform the Krebs cycle or oxidative phosphorylation. They rely entirely on glycolysis.

Step 3: Reasoning
Leucocytes possess mitochondria and can perform the full aerobic respiratory pathway. The question seeks a common pathway. While both perform glycolysis.

Step 4: Conclusion
According to the official key, oxidation of acetyl-CoA is the selected commonality. Final Answer: (B)