Biological Membrane

Fluid Mosaic Model

theory of cell membrane structure with proteins embedded in a sea of phospholipids.

Glycolipid

lipid/phospholipid with a chain of carbohydrate molecules attached.

Glycoprotein

protein with a chain of carbohydrate molecules attached.

Plasma Membrane

Cell surface membrane

Diffusion


movement of molecules from an area of high concentration to an area of low concentration; it does not involve ATP.

Facilitated diffusion


diffusion across a partially permeable membrane via protein channels or carriers; it does not involve ATP.


osmosis

passage of water molecules down their water potential gradient, across a partially permeable membrane.

Water potential


measure of the tendency of water molecules to diffuse from one region to another.

Active transport

the movement of substances against their concentration gradient, across a plasma membrane, using ATP and protein carriers.

Endocytosis


bulk transport of molecules, too large to pass through a plasma membrane even via channel or carrier proteins, into a cell.

Exocytosis

bulk transport of molecules, too large to pass through a plasma membrane even via channel or carrier proteins, out of a cell.

Crenated

a shrivelled animal cell that has lost water by osmosis.

Flaccid

plant tissue where there is no turgor- the tissue is soft.

Plasmolysed

plant cell where the contents have shrunk due to loss of water by osmosis and the plasma membrane has separated from the cell wall.


Turgid

a swollen state of plant cells that have taken in water by osmosis and reached their maximum state of swelling.

Glycocaylx


all of the carbohydrate molecules on the exterior of a plasma membrane.