One of protein function is transporting of other substances. It is specific group of the body’s proteins specialize in moving nutrients and other molecules.
Transport protein regulate the flow of substance (including nutrients) into and out of the cell.
Transport proteins may function by acting as carriers or they may provide protein-lined passages through which water soluble materials of small molecular weight may diffuse.
The ability to bind other molecules is common to many proteins. Binding proteins typically interact noncovalently with their specific ligands. Transport proteins are one class of binding protein.
For example, hemoglobin, the iron-containing protein of blood, transport oxygen from the lungs to other parts of the body. Other proteins transport molecules across cell membranes.
Hemoglobin bind specific ligands, in this case oxygen and transport the ligand to a site where it is needed. Other transport proteins move about in the body fluids, carrying nutrients and other molecules from one organ to another.
Those that carry lipids in the lipoproteins are examples. Transport protein have evolved in numerous occasions to catalyze migration of a solute or the solvent across biomembranes.
Special proteins also can carry fat-soluble vitamins, water-soluble vitamins, and minerals.
Therefore, a protein deficiency can cause a vitamin A deficiency or a deficiency of whatever other nutrient needs a transport protein to reach its destination in the body.
Transport Proteins
