Question

More than half a century ago, two cell biologists published details of their research involving isolated membrane vesicles from chloroplasts. Normally, the fluid inside these vesicles is near neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until the inside of the vesicle also became pH 4. Based on the details provided in this scenario, by what mechanism could hydrogen ions have crossed the vesicle membrane, and what do you think happened at the molecular level?

Answer 1

Answer:

Plasma membrane is the semi-permeable membrane that allow the movement of some selected particles only against the concentration gradient or along the concentration gradient.

Different substances can be move through the diffusion, active process and passive process. The hydrogen in the vesicle has been moved through the facilitated diffusion.  In this process, the hydrogen ions will move along the concentration gradient without the requirement of energy but requires the channel protein for its transport.