Chapter 7 Cell Membrane Flashcards

491001502	diffusion	When a substance moves from an area of higher concentration to an area of lower concentration. Due to entropy.	0
491001503	osmosis	The diffusion of water through a selectively permeable membrane.	1
491001504	dialysis	The diffusion of small solutes through a selectively permeable membrane.	2
491001505	passive transport	Transport of a substance across a cell membrane by diffusion. Going with a concentration gradient.	3
491001506	active transport	When a cell gets materials or excretes them by using its own energy, usually through ATP; going against a concentration gradient.	4
491001507	hypertonic	Describes a solution that has a greater concentration of total solute.	5
491001508	hypotonic	Describes a solution that has a lesser concentration of total solute.	6
491001509	isotonic	Describes solutions that have an equal concentration of total solutes.	7
491001510	turgor pressure	The pressure inside of a cell as a cell pushes itself against the cell wall.	8
491001511	plasmolysis	This happens when a cell shrinks inside its cell wall while the cell wall remains intact.	9
491001512	flaccid	This happens when water moves, but the amount within the cell is constant; no pressure builds.	10
491001545	turgid	A cell with a cell wall that has a reasonable amount of pressure but is healthy.	11
491001513	cytolysis	This happens when a cell swells until pressure bursts it, resulting in cell death.	12
491001514	crenation	This happens when a cell shrinks and shrivels; can result in cell death if severe.	13
491001515	water potential	The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.	14
491001516	solute potential	This measurement has a maximum value of 0; it decreases as the concentration of a solute increases.	15
491001517	pressure potential	This measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases.	16
491001518	selective permeability	A property of a plasma membrane that allows some substances to cross more easily than others.	17
491001519	amphipathic	Molecules are said to be this when it has regions that are both hydrophilic and hydrophobic.	18
491001520	fluid mosaic model	Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.	19
491001521	integral proteins	Transmembrane proteins with hydrophobic regions that completely span the hydrophobic interior of the membrane.	20
491001522	transmembrane proteins	Integral proteins that span the membrane.	21
491001523	peripheral proteins	The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.	22
491001524	transport	An exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes.	23
491001525	enzymatic activity	A protein built into the membrane with active site exposed.	24
491001526	signal transduction	A series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell.	25
491001527	cell-cell recognition	The function of membrane proteins in which some glycoproteins serve as ID tags that are recognized by membrane proteins of other cells.	26
491001528	intercellular joining	The function of membrane proteins in which membrane proteins of adjacent cells hook together, as in gap junctions or tight junctions.	27
491001530	glycolipids	Membrane carbohydrates that are covalently bonded to lipids.	28
491001531	glycoproteins	Membrane carbohydrates that are covalently bonded to proteins.	29
491001536	transport protein	A membrane protein that is responsible for moving hydrophilic substances from one side to the other.	30
491001537	channel protein	A membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel.	31
491001538	aquaporin	A membrane protein, specifically a transport protein, that facilitates the passage of water through channel proteins.	32
491001539	carrier protein	A membrane protein, specifically a transport protein, that holds onto molecules and changes their shapes in a way that shuttles them across the membrane.	33
491001540	concentration gradient	A difference in the concentration of a substance across a distance.	34
491001543	tonicity	The ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell.	35
491001544	osmoregulation	The control of water balance.	36
491001547	facilitated diffusion	Passive diffusion that is aided by transport proteins, but that does not require cellular energy.	37
491001548	membrane potential	The voltage of a plasma membrane.	38
491001550	electrochemical gradient	The combination of forces that acts on membrane potential.	39
491001555	gated channel	A protein channel in a cell membrane that opens or closes in response to a particular stimulus.	40
491001556	electrogenic pump	A transport protein that generates voltage across a membrane, causing a net separation in charge.	41
491001557	proton pump	An electrogenic pump that works largely with H+ ions.	42
491001558	cotransport	The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient.	43
491001559	exocytosis	Occurs when a cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane.	44
491001560	endocytosis	Occurs when a cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane.	45
491001561	phagocytosis	Process in which extensions of cytoplasm surround and engulf large particles and take them into the cell.	46
491001562	pinocytosis	A type of endocytosis in which the cell "gulps" droplets of fluid into tiny vesicles.	47
491001563	receptor-mediated	A type of endocytosis in which the cell acquires bulk quantities of specific substances, even though they may not be very concentrated in the extracellular fluid.	48
491001564	ligand	Any molecule that bonds specifically to a receptor site of another molecule.	49