AP Biology: Chapter 7 Flashcards

7987176738	Active Transport	The movement of a substance across a biological membrane against its concentration or electrochemical gradient	0
7987176739	Amphipathic Molecule	A molecule that has both a hydrophilic region and a hydrophobic region	1
7987176740	Aquaporins	A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across a membrane	2
7987176741	Concentration Gradient	An increase or decrease in the number of particles per volume of a chemical substance in an area	3
7987176742	Cotransport	The coupling of the "downhill" diffusion of one substance with the "uphill" transport against its own concentration gradient	4
7987176743	Diffusion	the process by which molecules move from an area of higher concentration to an area of lower concentration	5
7987176744	Electrochemical Gradient	The diffusion gradient of an ion, which is affected by both the concentration difference of the ion across a membrane (a chemical force) and the ion's tendency to move relative to the membrane potential (an electrical force).	6
7987176745	Electrogenic Pump	An active transport protein that generates voltage across a membrane while pumping ions.	7
7987176746	Endocytosis	the process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell	8
7987176747	Exocytosis	the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out	9
7987176748	Facilitated Diffusion	the transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins	10
7987176749	Flaccid	Limp. Lacking in stiffness or firmness, as in a plant cell in surroundings where there is no tendency for water to enter the cell.	11
7987176750	Fluid Mosaic Model	The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.	12
7987176751	Gated Channels	A protein channel in a cell membrane that opens or closes in response to a particular stimulus.	13
7987176752	Hypertonic	When comparing two solutions, the solution with the greater concentration of solutes	14
7987176753	Hypotonic	When comparing two solutions, the solution with the lesser concentration of solutes	15
7987176754	Ion Channels	A transmembrane protein channel that allows a specific ion to flow across the membrane down its concentration gradient	16
7987176755	Isotonic	When comparing two solutions, both have a solute concentration equal to that of the other solution	17
7987176757	Membrane Potential	The charge difference between a cell's cytoplasm and the extracellular fluid, due to the differential distribution of ions.	18
7987176758	Osmoregulation	The control of water balance in organisms living in hypertonic, hypotonic, or terrestrial environments.	19
7987176759	Osmosis	diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal	20
7987176760	Passive Transport	The movement of substances across a cell membrane without the use of energy by the cell.	21
7987176761	Plasmolysis	When a cell is in a hypertonic environment, the cell will lose water to its surroundings, shrink, and its plasma membrane will pull away from the wall	22
7987176762	Proton Pump	An active transport mechanism in cell membranes that consumes ATP to force hydrogen ions (H+) out of a cell and, in the process, generates a membrane potential	23
7987176763	Selective Permeability	A property of biological membranes that allows some substances to cross more easily than others.	24
7987176764	Sodium-potassium pump	A special transport protein in the plasma membrane of animal cells that transports sodium out of the cell and potassium into the cell against their concentration gradients.	25
7987176765	Tonicity	The ability of a solution to cause a cell within it to gain or lose water.	26
7987176766	Transport Proteins	Protein molecules that help to transport substances throughout the body and across cell membranes	27
7987176767	Turgid	Firm. Walled cells become turgid as a result of the entry of water from a hypotonic environment.	28
7987176768	Extracellular Matrix	A collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells.	29
7987176769	Carbohydrate chain	Made up of sugar molecules and can be joined to protein for cell communication and identification.	30
7987176770	Glycoprotein	Proteins that have carbohydrates covalently bonded to them.	31
7987176771	Cholesterol	Steroid present in the plasma membranes of animal cells. A large amount of this in a phospholipid bilayer at High Temperatures reduces membrane fluidity, but at Lower Temperatures prevents the membrane from solidifying.	32
7987176772	Microfilaments of cytoskeleton	Provide structure and support to the cell, allow for movement and stabilization of organelles.	33
7987176773	Peripheral protein	Bound to the surface of the membrane and integral proteins, but not embedded in the lipid bilayer.	34
7987176774	Glycolipid	Fatty acids with linked sugar groups that are key structural elements in cell membranes and precursors of other biologically active molecules important in cell signaling	35
7987176775	Integral protein	Extend entirely through the membrane with both hydrophobic and hydrophilic ends (imbedded)	36