passive transport involves the movement of molecules across the cell membrane without an imput of energy by the cell.
diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, driven by the molecules' kinetic energy until equilibrium is reached.
a difference in the concentration of a substance across a distance
in biology, a state that exists when the concentration of a substance is the same throughout a space
is the diffusion of water across a cell membrane by dissolving in the phospholipid bilayer or by passing through pores in the membrane
when the solute concentration outside the cell is lower than that in the cytosol the solution outside is hypotonic to the cytosol, and water will diffuse into the cell
when the solute concentration outside the cell is higher than that in the cytosol, the solution outside is hypertonic to the cytosol, and the water will diffuse out of the cell
when the solute concentrations outside and inside the cell are equal, the solution outside is isotonic, and there will be no net movement of water
in protists, an organelle that accumulates water and then releases it periodically to maintain osmotic pressure
the pressure that is exerted on the inside of cell walls and that is caused by the movement of water into the cell
the contraction or shrinking of the cell membrane of a plant cell in a hypertonic solution in response to the loss of water by osmosis
the bursting of a cell
when a molecule binds to a carrier protein on one side of the cell membrane. The carrier protein then changes its shape and transports the molecule down its concentration gradient to the other side of the membrane
a protein that transports substances across a cell membrane
proteins, or groups of proteins that provide passage across the cell membrane, this allows specific ions to diffuse
moves molecules across the cell membrane from an area of lower concentration to an area of higher concentartion. unlike passive transport, active transport requires cells to expend energy.
a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell
the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell
a small cavity or sac that contains materials in a eukaryotic cell; forms when part of the cell membrane surrounds the materials to be taken into the cell or transported within the cell
a method of active transport across the cell membrane in which the cell takes in extracellular fluids
the process by which a cell engulfs large particles or whole cells, either as a defense mechanism or as a means to obtain food
a cell that ingests and destroyds foreign matter of microorganisms
the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out