AP Biology: Chapter 5 Flashcards

8001688703	Active Transport	The movement of a substance across a biological membrane against its concentration or electrochemical gradient	0
8001688704	Amphipathic Molecule	A molecule that has both a hydrophilic region and a hydrophobic region	1
8001688705	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
8001688706	Concentration Gradient	An increase or decrease in the number of particles per volume of a chemical substance in an area	3
8001688707	Cotransport	The coupling of the "downhill" diffusion of one substance with the "uphill" transport against its own concentration gradient	4
8001688708	Diffusion	the process by which molecules move from an area of higher concentration to an area of lower concentration	5
8001688709	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
8001688710	Electrogenic Pump	An active transport protein that generates voltage across a membrane while pumping ions.	7
8001688711	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
8001688712	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
8001688713	Facilitated Diffusion	the transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins	10
8001688714	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
8001688715	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
8001688716	Gated Channels	A protein channel in a cell membrane that opens or closes in response to a particular stimulus.	13
8001688717	Hypertonic	When comparing two solutions, the solution with the greater concentration of solutes	14
8001688718	Hypotonic	When comparing two solutions, the solution with the lesser concentration of solutes	15
8001688719	Ion Channels	A transmembrane protein channel that allows a specific ion to flow across the membrane down its concentration gradient	16
8001688720	Isotonic	When comparing two solutions, both have a solute concentration equal to that of the other solution	17
8001688721	Ligands	A molecule that binds specifically to a receptor site of another molecule.	18
8001688722	Membrane Potential	The charge difference between a cell's cytoplasm and the extracellular fluid, due to the differential distribution of ions.	19
8001688723	Osmoregulation	The control of water balance in organisms living in hypertonic, hypotonic, or terrestrial environments.	20
8001688724	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	21
8001688725	Passive Transport	The movement of substances across a cell membrane without the use of energy by the cell.	22
8001688726	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	23
8001688727	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	24
8001688728	Selective Permeability	A property of biological membranes that allows some substances to cross more easily than others.	25
8001688729	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.	26
8001688730	Tonicity	The ability of a solution to cause a cell within it to gain or lose water.	27
8001688731	Transport Proteins	Protein molecules that help to transport substances throughout the body and across cell membranes	28
8001688732	Turgid	Firm. Walled cells become turgid as a result of the entry of water from a hypotonic environment.	29
8001688733	Extracellular Matrix	A collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells.	30
8001688734	Carbohydrate chain	Made up of sugar molecules and can be joined to protein for cell communication and identification.	31
8001688735	Glycoprotein	Proteins that have carbohydrates covalently bonded to them.	32
8001688736	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.	33
8001688737	Microfilaments of cytoskeleton	Provide structure and support to the cell, allow for movement and stabilization of organelles.	34
8001688738	Peripheral protein	Bound to the surface of the membrane and integral proteins, but not embedded in the lipid bilayer.	35
8001688739	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	36
8001688740	Integral protein	Extend entirely through the membrane with both hydrophobic and hydrophilic ends (imbedded)	37
8001713734	Water potential	Substances diffuse from high areas to low areas. Solute potential + pressure potential	38
8001732846	Solute potential	With increased concentration this becomes more negative, thus causing a decrease in water potential.	39
8001747336	Pressure potential	Has a direct correlation with total water potential. Positive pressure within plant cells is called, turgor pressure.	40