Kidney collecting duct cells have aquaporin channels in their membranes. When the hormone vasopressin signals dehydration, more aquaporins are inserted, and water reabsorption rises sharply. Sodium/potassium permeability is unchanged.
Aquaporins are an example of which transport process?
- Acheck_circle
Facilitated diffusion of water through a selective channel (no ATP)
- B
Active transport of water that requires ATP
- C
Endocytosis of water droplets
- D
Ion pumping that secondarily moves water
Explanation
Aquaporins are channel proteins that allow water to follow its osmotic gradient passively, no ATP required - the hallmark of facilitated diffusion.