AP Biology Unit 2 - Chapter 7 Membranes Flashcards

8185159733	plasma membrane	seperates the living cell from its surroundings. Contros traffic in and out of the cell. Is selectively permeable.	0
8185159734	selectively permeable	allows some substances to cross more easily than others.	1
8185159735	phospholipids	most abundant lipids	2
8185159736	lipids and proteins	main macromolecules in membranes	3
8185159737	amphipatic molecules	have hydrophobic and hydrophilic regions	4
8185159738	fluid mosaic model	The arrangement of phospholipids and proteins in biological membranes is described by the...	5
8185159740	transmembrane proteins	the integral protein completely spans the membrane as...	6
8185159741	integral proteins	proteins that penetrate the hydrophobic interior of the lipid bilayer	7
8185159742	peripheral proteins	proteins that are not embedded in the lipid bilayer	8
8185159743	cell-cell recognition	the ability of a cell to disitnguish one type of neighboring cell from another.	9
8185159745	transport proteins	proteins that span the membrane.	10
8185159746	channel proteins	transport proteins that have a hydrophilic channel that certain molecules or ions use as a tunnel though the membrane.	11
8185159747	aquaporins	channel proteins that facilitate the passage of water	12
8185159748	carrier proteins	transport proteins that bind to molecules and change shape to shuttle them across the membrane.	13
8185159749	diffusion	movement of molecules of any substance to spread out in available space	14
8185159750	concentration gradient	the region along which the density of a chemical substance increases or decreases.	15
8185159751	passive transport	transport that requires no energy from the cell to make it happen	16
8185159752	osmosis	the diffusion of water across a selectively permeable membrane	17
8185159753	tonicity	the ability of a surrounding solution to cause a cell to gain or lose water.	18
8185159754	isotonic (animal cell)	if a cell with no cell wall is immersed in an enviroment where there is no net movement of water across the plasma membrane. Stays the same.	19
8185159755	hypertonic (animal cell)	when the cell is immersed in a solution where it loses water to its environment, shrivels and probably dies.	20
8185159756	hypotonic (animal cell)	when a cell is immersed in a solution, water enters the cell faster than it leaves, it swells and lyses (explodes) like an overfilled water balloon.	21
8185159759	turgid	when the plant cell is very firm, which is a healthy state for most plant cells.	22
8185159760	hypotonic (plant cell)	when a plant cell is immersed in a __________ solution the cell contents swell due to osmosis until the elastic cell wall exerts turgor pressure on the cell that opposes further water outake.	23
8185159761	isotonic (plant cell)	when a plant cell is immersed in a _______ solution; there is no net movement. The cell becomes flaccid and the plant may wilt.	24
8185159762	flaccid	limp, not firm or strong (If a plant is not watered enough, its leaves become droopy and flaccid.)	25
8185159763	hypertonic (plant cells)	the plant cell loses water, its volume shrinks. The plasma membrane pulls away from the wall, this is plasmolysis. It is lethal to the cell.	26
8185159764	plasmolysis	This happens when a cell shrinks inside its cell wall while the cell wall remains intact. The plasma membrane pulls away from the wall.	27
8185159765	facilitated diffusion	the passive movement of molecules down their concentration gradient with the help of transport proteins.	28
8185159766	ion channels (gated channels)	Channels that open or close depending on the presence or abscence of an electrical, chemical, or physical stimulus.	29
8185159768	active transport	transport that requires the cell to expend metabolic energy and enables a cell to maintain internal concentrations of small molecules. Requires energy.	30
8185159769	ATP	supplies energy for most active transport	31
8185159770	sodium-potassium pump	transport protein that, translocating the bound solute across the membrane. Exchanges sodium ions (Na) for potassium ions (K) across the plasma membrane of animal cells.	32
8185159774	sodium-potassium pump	major electrogenic pump in animals. Restores the electrochemical gradient by setting up a concentration gradient. It pumps 2 K ions for every 3 Na ions that it moves out, it generates a voltage.	33
8185159777	exocytosis	transport vesicle budded from the Golgi apparatus is moved by the cytoskeleton to the plasma membrane. When the 2 membranes come in contact, the bilayers fuse spill the contents.	34
8185159778	endocytosis	a cell brings in biological molecules and particulate matter by forming new vesicles from the plasma membrane. 3 types: phagocytosis, pinocytosis and receptor-mediated endocytosis.	35
8185159779	phagocytosis	a cell engulfs a particle in a vacuole. The vacuole fuses with a lysosome to digest the particle.	36
8185159780	pinocytosis	molecules are taken up when extracellular fluid is "gulped" into tiny vesicles.	37
8185159781	receptor-mediated endocytosis	endocytosis that enables a cell to acquire bulk quantities of specific materials that may be in low concentrations in the environment.	38
8185159782	lipoproteins	complexes of proteins and lipids. Cholesterol travels in low density _______	39
8185159783	ligands	A molecule that binds specifically to a receptor site of another molecule.	40