How various mechanisms by which substances cross the cell membrane

…

…is hydrolyzed and the phosphate group is transferred we call it phosphorylation. In review, substances cross the cell membrane in two different ways: passive and active transport. Passive transport includes osmosis, diffusion, and facilitated diffusion. None of these techniques use energy. Active transport includes endo and exocytosis, sodium-potassium pumps. and phosphorylation, all of which expend energy to transport substances across the cell membrane. The cell has the ability to regulate what crosses its cellular boundaries.