Question

The Fe₃⁺ iron in the plasma is bound to transferrin for transport in the blood. If not transferred to the plasma, iron is stored as ferritin in the cell and lost in the feces when the intestinal cell sloughs. What is the role of transferrin in the transport of iron in the blood?

1) Transferrin helps in the absorption of iron from the intestines.
2) Transferrin helps in the storage of iron in the cells.
3) Transferrin helps in the transport of iron in the blood.
4) Transferrin helps in the excretion of iron through feces.

Answer 1

Transferrin functions as the transport protein for iron in the blood, carrying the iron in the ferric state (Fe³⁺) to various cells and allowing its release for immediate use or storage in the form of ferritin.

Step-by-step explanation:

The role of transferrin is crucial in the transport of iron in the blood. This protein binds to iron in the ferric state (Fe³⁺) in the plasma, forming a transferrin-iron complex which is responsible for the delivery of iron to various cells throughout the body. Once the iron-transferrin complex reaches a cell, iron is then released from transferrin by reduction to Fe²⁺, following which it can be used immediately for biological processes such as the synthesis of hemoglobin, or stored within cells as ferritin.