While testing the chemiosmotic theory across the domains of life, researchers prepared "inside-out" vesicles from bacterial plasma membranes, mitochondrial internal membranes, and chloroplast thylakoids. An inside-out vesicle is a
A) vesicle in which the F1 subunit of the proton-ATPase faces outward.
B) membrane in which the hydrophobic tails of the phospholipids face outward.
C) cell that has been enzymatically stripped of its cell wall.
D) preparation of outer membranes in Gram-negative bacteria, chloroplast envelopes, and mitochondria outer membranes.
E) preparation from bacterial cytoplasm, chloroplast stroma, and mitochondrial matrix.

Question

Quizplus · Accepted Answer

An inside-out vesicle is one in which the orientation of the membrane is reversed, so that the side of the membrane that is normally facing the interior (cytoplasmic side) of the cell or organelle is facing outward. The F1 subunit of the proton-ATPase, which is normally oriented towards the interior, would face outward in such a vesicle. This is useful in experimental setups to study membrane-bound enzymes and transport processes.

While Testing the Chemiosmotic Theory Across the Domains of Life