How does water move through aquaporin?

The movement of water through the aquaporins is driven by osmotic gradients. For example, red cells dropped into seawater will shrink because water leaves the cells; red cells dropped into fresh water will swell and explode since water enters the cell.

What process do aquaporins use?

However, because water is a polar molecule this process of simple diffusion is relatively slow, and the majority of water passes through aquaporin….

How are aquaporins activated?

The discovery of water channels (aquaporins) was a breakthrough in research on water transport. Aquaporin-2 is the only water channel that is activated by vasopressin to enhance water reabsorption in the kidney collecting duct.

What type of membrane transport occurs through an aquaporin?

It is important to remember that aquaporins do not actively transport water across the cell membrane; instead they facilitate the diffusion of water across the cell membrane.

What does an aquaporin do?

Aquaporins are membrane channels expressed in almost every organism and involved in the bidirectional transfer of water and small solutes across cell membranes.

What type of molecule is transported by aquaporins?

The classical aquaporins transport solute-free water across cell membranes; they appear to be exclusive water channels and do not permeate membranes to ions or other small molecules. Some aquaporins – known as aquaglyceroporins – transport water plus glycerol and a few other small molecules.

Is aquaporin regulated?

Eukaryotic aquaporins are frequently regulated post-translationally by gating, whereby the rate of flux through the channel is controlled, or by trafficking, whereby aquaporins are shuttled from intracellular storage sites to the plasma membrane.