AP Bio Chapter 7 Flashcards

443315343	diffusion	when a substance moves from an area of higher concentration to an area of lower concentration; caused by entrapy because nature wants stability	0
443315344	osmosis	the diffusion of water through a selectively permeable membrane	1
443315345	dialysis	the diffusion of small solutes through a selectively permeable membrane	2
443315346	passive transport	diffusion or osmosis; the way a cell gets materials or excretes them by having them go from a high concentration to a low concentration; no ATP is necessary, energy comes from normal collisions; slow over large distances	3
443315347	active transport	when a cell gets materials or excretes them by using its own energy, usually through ATP; going against natural tendencies	4
443315348	hypertonic	describes a solution that has a greater concentration of total solute	5
443315349	hypotonic	describes a solution that has a lesser concentration of total solute	6
443315350	isotonic	describes solutions that have an equal concentration of total solutes	7
443315351	turgor pressure	the pressure inside of a cell as a cell pushes itself against the cell wall	8
443315352	plasmolysis	this happens when a cell shrinks inside its cell wall while the cell wall remains intact; concentration of water decreases, while solute concentration increases	9
443315353	flaccid	this happens when water moves, but the amount within the cell is constant; no pressure builds	10
443315354	crenation	this happens when a cell shrinks and shrivels; can result in cell death if severe	11
443315355	water potential	this states that water will always move from an area with high water potential to an area with low water potential	12
443315356	solute potential	this measurement has a maximum value of 0; it decreases as the concentration of a solute increases	13
443315357	pressure potential	this measurement has a minimum value of 0 (when the solution is open to the environment); it increases as pressure increases	14
443315358	selective permeability	a property of a plasma membrane that allows some substances to cross more easily than others	15
443315359	amphipathic	molecules are said to be this when it has regions that are both hydrophilic and hydrophobic	16
443315360	fluid mosaic model	the currently accepted arrangement of membranes; it is a fluid structure with a "mosaic" of various proteins embedded in or attached to a double layer of phospholipids; proposed by Singer and Nicolson in 1972	17
443315361	integral proteins	the proteins of a membrane that penetrate the hydrophobic core of the lipid bilayer; hydrophobic regions consist of nonpolar amino acids, while hydrophilic regions are exposed to aqueous solution on either side of membrane	18
443315362	transmembrane proteins	the proteins of a membrane that span the entire membrane	19
443315363	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, often exposed to parts of the integral proteins; attached by cytoskeleton on cytoplasmic side, and by fibers of ECM on extracellular side	20
443315364	transport	the function of membrane proteins that allows travel through a hydrophilic channel, or by transport proteins, which shuttle molecules across the membrane by changing shape with the help of hydrolyzing ATP	21
443315365	enzymatic activity	the function of membrane proteins that uses the exposure of proteins' active sites to adjacent solutions; metabolic processes progress to help substances pass	22
443315366	signal transduction	the function of membrane proteins that allow proteins to have binding sites with specific shapes that fit chemical messengers; external messengers may cause a shape change in protein that relays a message to the inside of the cell, usually by binding to a cytoplasmic protein	23
443315367	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	24
443315368	intercellular joining	the function of membrane proteins in which membrane proteins of adjacent cells hook together, as in gap junctions or tight junctions	25
443315369	attachment to cytoskeleton and extracellular matrix	the function of membrane proteins in which microfilaments bond noncovalently to membrane proteins, maintaining cell shape and protein location; proteins bound to extracellular matrix molecules can coordinate extracellular and intracellular changes	26
443315370	glycolipids	membrane carbohydrates that are covalently bonded to lipids	27
443315371	glycoproteins	membrane carbohydrates that are covalently bonded to proteins	28
443315372	transport protein	a membrane protein that is responsible for moving hydrophilic substances from one side to the other	29
443315373	channel protein	a membrane protein, specifically a transport protein, that has a hydrophilic channel that certain molecules or atomic ions use as a tunnel	30
443315374	aquaporin	a membrane protein, specifically a transport protein, that facilitates the passage of water through channel proteins	31
443315375	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	32
443315376	concentration gradient	the region along which the density of a substance decreases	33
443315377	up	when a substance diffuses from an area of lower concentration to an area of higher concentration, it is moving ______ its concentration gradient	34
443315378	down	when a substance diffuses from an area of higher concentration to an area of lower concentration, it is moving ________ its concentration gradient	35
443315379	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	36
443315380	osmoregulation	the control of water balance	37
443315381	turgid	a cell with a cell wall that has a reasonable amount of pressure but is healthy	38
443315382	flaccid	a cell with a cell wall that is in an isotonic solution that allows for a steady volume	39
443315383	facilitated diffusion	passive diffusion that is aided by transport proteins, but that does not require cellular energy	40
443315384	membrane potential	the voltage of a plasma membrane; ranges from -50 mV to -200 mV; the (-) signifies in which direction the substances move--(-) = outside of cell	41
443315385	membrane potential	favors the passive transport of cations into the cell and anions out of the cell	42
443315386	electrochemical gradient	the combination of forces that acts on membrane potential	43
443315387	nonpolar	when ____________ entities hit the membrane, they dissolve through it and pass through the membrane and into the cell	44
443315388	ionic	when ____________ entities hit the membrane, they accompany a protein in order to be dissolved, regardless of size	45
443315389	small nonpolar	when ____________ entities hit the membrane, they pass through the membrane alone	46
443315390	large polar	when ____________ entities hit the membrane, they are completely blocked from entering	47
443315391	gated channel	a highly selective tunnel on a plasma membrane that can open or close depending on conformational changes; they are changed due to electrical disturbances, bonding of a specific ligand; allows a substance to diffuse	48
443315392	electrogenic pump	a transport protein that generates voltage across a membrane, causing a net separation in charge	49
443315393	proton pump	an electrogenic pump that works largely with H+ ions in plants, fungi, and bacteria	50
443315394	cotransport	a mechanism through which a single ATP-powered pump that transports a specific solute can indirectly drive the active transport of several other solutes; substances that have been pumped across membrane can do work as they move back across the membrane by diffusion	51
443315395	exocytosis	occurs when a cell secretes certain biological molecules by the fusion of vesicles with the plasma membrane	52
443315396	endocytosis	occurs when a cell takes in biological molecules and particulate matter by forming new vesicles from the plasma membrane	53
443315397	phagocytosis	a type of endocytosis in which the cell engulfs a particle by wrapping pseudopodia around it and packaging it within a membrane-enclosed sac that can be large enough to be considered a vacuole; particle is digested after vacuole fuses with lysosome	54
443315398	pinocytosis	a type of endocytosis in which the cell "gulps" droplets of fluid into tiny vesicles; molecules dissolved in liquid are necessary for cell; nonspecific in substances it transports	55
443315399	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; receptor proteins are already clustered in regions of membrane called coated pits, which are lined on cytoplasmic side by fuzzy layer of coat proteins; when ligands bond to receptors, coated pits form a vesicle that contains ligand molecules	56
443315400	ligand	any molecule that bonds specifically to a receptor site of another molecule	57