condition of continuous, random movement of particles but no overall change in concentration of materials

passive transport of ions and small molecules across the plasma membrane by transport proteins

diffusion of water across a selectively permeable membrane

a solution with the same concentration of water and solutes as inside a cell, resulting in the cell retaining its normal shape because there is no net movement of water.

a solution that has a lower concentration of solute outside than inside the cell, causing water to flow into the cell by osmosis

a solution that has a higher concentration of solute outside than inside a cell, causing water to leave the cell by osmosis.

energy-requiring process by which substances move across the plasma membrane against a concentration gradient

energy-requiring process by which large substances from the outside environment can enter a cell

energy-requiring process by which a cell expels wastes and secretes substances at the plasma membrane.