You have prepared lipid vesicles that contain molecules of t

You have prepared lipid vesicles that contain molecules of the leak K+ channels, all oriented so that their cytosolic surface faces the outside of the vesicle. Predict how K+ will move under the following conditions and what sort of membrane potential will develop

(a) Equal concentrations of K+ ions are present inside and outside the vesicles

(b) K+ ions are present only inside the vesicles.

(c) K+ ions are present only outside the vesicles.

Solution

Normally K+ ion concentration inside the cell is higher as compared to the outside of a cell but the movemnet of K+ion across the membrane dpends on its concentration and thus generate a membrane potential.

(a) equal concentration of K+ ion inside and outside the vesicle will not generate any membrane potential and will generate a net zero potential

(b) if K+ ion present only inside the vesicles so will generate a membrane potential and it will try to escape the interior through leaky channel and membrane will feel deporarization means a more negative (-70 to -60)

(c) if K+ ion is present only outside of the vesicle it means membrane is under hyperpolarization state which means even more negative and K+ ion will try to come inside the vesicle by concentration gradient and try to maintain the resting potential.