contractile vacuole
gets rid of excess water in the cell (paramecium)
passive transport
membrane transport that does not require energy to move substances across cell membranes
hypotonic
The solution has less solute than the cell, water will move into the cell and solute out (if it can pass through membrane)
plasmolysis
the cell shrinks ( more flaccid) because water is moving out of the cell
diffusion
the net movement of anything from a region of higher concentration to a region of lower concentration
hypertonic
The solution has more solute than the cell, water will move out of the cell and solute in (if it can pass through membrane)
cytolysis
the cell swells (more turgid) because water is moving into the cell
concentration gradient
occurs when the concentration of particles is higher in one area than another.
Isotonic
the solution has equal solute to the cell, water will move in and out of the cell maintaining dynamic equilibrium and the solute will do the same (if it can pass through the membrane)
facilitated diffusion
the diffusion of solutes through transport proteins in the plasma membrane
equilibrium
The condition in which all acting influences are balanced or canceled by equal opposing forces, resulting in no net change
carrier protein
transports certain biomolecules between cells
osmosis
movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell's partially permeable membrane.
turgor pressure
pressure that is exerted by the fluid (e.g. water) that pushes the plasma membrane against the cell wall
ion channel
pores in the cellular membrane that allow the passage of ions across the cell membrane
active transport
a process that involves the movement of molecules from a region of lower concentration to a region of higher concentration against a gradient or an obstacle with the use of external energy
pinocytosis
endocytosis when material taken in is a liquid
sodium-potassium pump
It acts to transport sodium and potassium ions across the cell membrane in a ratio of 3 sodium ions out for every 2 potassium ions brought in
phagocytosis (amoeba)
endocytosis when the material taken in is a bacterial cell or an organic fragment (food)
endocytosis
material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material
phagocyte
a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles
vesicle
a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. They form naturally during the processes of secretion, uptake and transport of materials within the plasma membrane.
exocytosis
a process by which the contents of a cell vesicle are released to the exterior through fusion of the vesicle membrane with the cell membrane