ISO membranes are inside-out membrane vesicles used by researchers in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order
A) head-tail-tail-head.
B) tail-head-tail-head.
C) head-tail-head-tail.
D) tail-head-head-tail.
E) head-head-tail-tail.

Question

Quizplus · Accepted Answer

The correct order in which a molecule diffuses into an ISO membrane vesicle and encounters the layers of the membrane is head-tail-tail-head. This reflects the bilayer structure of cell membranes, where the hydrophilic (water-attracting) head groups face outward towards the aqueous environment on both sides, and the hydrophobic (water-repelling) tails face inward, away from water.

ISO Membranes Are Inside-Out Membrane Vesicles Used by Researchers in Membrane