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Normal homeostatic conditions require potassium concentrations to be about 1000 times higher inside the cell than in the blood.

What mechanism does a cell use to move these small potassium molecules into the cell against the concentration gradient?

passive transport by osmosis
active transport by proteins
passive transport by diffusion
active transport by endocytosis

Answer 1

B

Answer 2

Since, the cell needs to move the potassium molecules against the concentration gradient, it needs to expend energy (because the the potassium molecules want to move with the concentration gradient). This is a process called active transport (meaning the cell is expending energy to transport molecule). Endocytosis is only really required for large molecules or even other cells. It involve the cell essentially wrapping around the object and forming a vacuole (a chamber for holding things) around it. Potassium is just a single ion, so it would not require endocytosis. So all you have left is active transport by proteins. B