AP BIOLOGY

Detailed explanation-1: -Aquaporins are found in a high concentration in the epithelial cells that produce aqueous humor (as well as other epithelial cells that allow water to move readily across their membrane, e.g., epithelial cells in the kidney). These pores allow water molecules through in a single file.

Detailed explanation-2: -The primary function of most aquaporins is to transport water across cell membranes in response to osmotic gradients created by active solute transport.

Detailed explanation-3: -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.

Detailed explanation-4: -The type of transport that occurs through aquaporins is a form of passive transport known as osmosis. Osmosis is the movement of water through a semipermeable membrane from high to low concentration.

Detailed explanation-5: -Aquaporins allow for the transport of water, called osmosis. During osmosis, water moves from where there is a lower concentration of solute to where there is a greater concentration of solute. This process occurs directly through the membrane to some degree, and to a greater extent through aquaporin proteins.