Question

"Water is absorbed in the intestine through which process"? a. simple diffusion b. active transport c. active diffusion d. facilitated diffusion e. gradient transport

Answer 1

Answer: Water is absorbed in the intestine through gradient transport. The correct option is E.

Explanation:

Absorption of water in the mammalian intestines occurs largely on the small intestine through a transport mechanism known as osmosis. Osmosis is the movement of water molecules, through a semi permeable membrane, from the region of lower solute concentration into higher solute concentration to attain an equilibrium.

For water molecules to be absorbed from the lumen into the bloodstream, it's dependent on sodium absorption. This follows the following steps:

-sodium is absorbed by co transport with glucose and amino acids.this aids to move sodium from lumen into the enterocyte.

- Rapid exportation of absorbed sodium through sodium pimps from the enterocyte.

- As sodium is pumped out of cells an osmotic gradient is formed across apical cell membrane, this helps to osmotically drive water across the epithelium. Therefore water is absorbed in the intestine through the osmotic gradient created by sodium absorption. I hope this helps. Thanks.