molecules move across the plasma membrane against their concentration gradient.
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
through facilitated diffusion or diffusion
Water crosses the plasma membrane
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of