Question

Are aquaporins used in osmosis?

Answer 1

Hint: If the cell requires a molecule, it does not matter if it’s a large molecule or a very polar molecule, the cell membrane will allow the molecule to pass through it. This might be done passively or through active transport.
The study of aquaporins and their function can help understand various skin conditions that occur due to an imbalance in water retention capacity.

Complete answer:
Passive transport ensures the movement of molecules down the concentration gradient across a cell membrane. The molecules move from a higher concentration region to a lower concentration region. Passive transport can be of three types- simple diffusion, facilitated diffusion, and osmosis. Molecules can easily diffuse into the cell through the cell membrane down its concentration gradient. Molecules (gases like oxygen, carbon dioxide, etc.) are small therefore, no energy is expended and no proteins are required for this transport.
Some large molecules (such as glucose, etc.) require proteins to facilitate their movement i.e. they require protein channels in the membrane to help enter or exit a cell. This is called facilitated diffusion. Solvent molecules, such as water, can enter or exit the cell. These solvent molecules move down the concentration gradient and are transported across the cell membrane. This is called osmosis. For doing so, aquaporins allow the cell membranes to regulate the internal osmotic pressure and volume in accordance with water moving in a direction from low to high concentration of salts.

Aquaporins in humans can selectively conduct water from in and out of the cell in the kidneys, lungs, and skeletal muscle.

Note:
Solvent molecules, such as water, can enter or exit the cell. These solvent molecules move down the concentration gradient and are transported across the cell membrane. This is called osmosis. it was thought that water could simply enter or exit the cell through osmosis. Water can osmotically move through these aquaporins to enter or leave the cell.