Now these is allow our body to actually fine tune these regulatory pathways to actually meet the needs and demands of all different types of cells that exist inside our body. Now, what I'd like to focus on in this lecture is the biochemical process by which we actually bring the glucose molecules into the cells of our body. So remember, glucose molecules have many polar groups, they have many hydroxyl groups, and that makes glucose a polar molecule. And so what that means is, even if we have a concentration gradient that exists across the cell membrane, because the membrane is predominantly nonpolar hydrophobic, these polar glucose molecules and sugar molecules cannot make their way across the cell membrane. And so the cells create these transmembrane proteins that contain twelve transmembrane alpha helices that we call glucose transporters. And these allow the movement, allow the shuttling of these glucose molecules across the cell membrane.