Question

Choose the correct sequence of events involved in receptor-mediated endocytosis of transferrin:

• A. D, A, B, E, C
• B. A, B, C, D, E
• C. D, A, B, C, E
• D. A, B, D, E, C

Hint:

Bind $\to$ Release (via pH change) $\to$ Recycle. The receptor is a “shuttle” that goes back for more.

Answer 1

The Correct Option is A

Step 1: Concept
Receptor-mediated endocytosis is the process by which cells absorb specific molecules via receptor-coated vesicles.

Step 2: Meaning
Transferrin delivers iron into cells via this pathway.

Step 3: Analysis
Receptors bind transferrin and deliver it to early endosomes (D). A specific pH environment induces iron release (A then B). The receptor along with apotransferrin is recycled to the plasma membrane (E). Remaining components are degraded (C).

Step 4: Conclusion
The sequence is D $\to$ A $\to$ B $\to$ E $\to$ C.

Final Answer: (A)