MEDICAL PHYSIOLOGY

Detailed explanation-1: -Aquaporin-1 (AQP1) is a membrane channel that allows rapid water movement driven by a transmembrane osmotic gradient. It was claimed to have a secondary function as a cyclic nucleotide-gated ion channel.

Detailed explanation-2: -Specifically, aquaporins are found in the vacuolar membrane, in addition to the plasma membrane of plants; the transcellular pathway involves transport of water across the plasma and vacuolar membranes.

Detailed explanation-3: -The aquaporins have high water permeability and selectivity because they are water channel proteins found in biological membranes.