Ionic iron is actively transported into the mucosal cells, where it binds to the protein ferritin, a phenomenon called the mucosal iron barrier. true / false.

True

Explanation:

The ionic form of iron (Fe2+ and Fe3+) can damage the molecules present in the cell and in the blood. Protective protein escorts namely transferring and ferritin bind to the ionic form of iron during its transport and storage.

In small intestine during absorption, the ionic form of iron is actively transported into the mucosa of intestinal lining. Once inside the mucosal cells, it binds to the ferritin protein. These iron-ferritin complexes of mucosal cells are the stored form of iron.

Following its active absorption, the binding of iron to ferritin in mucosal cells of intestinal lining is referred to as the mucosal iron barrier. When needed, a few of the stored iron is passed into the portal blood while the major proportion of the stored iron is released from the barrier only when the epithelial cells are sloughed off.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.