BIOL 101 Chp 7 Membrane Structure and Function Flashcards
This flash card set includes the vocabulary words and definitions from Chp 7: Membrane Structure and Function (Biology 8E by Campbell et al, 2008).
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| 41457411 | selective permeability | property of the plasma membrane that allows some substances to cross it more easily than others | |
| 41457412 | amphipathic | a molecule having both a hydrophilic region and a hydrophobic region | |
| 41457413 | fluid mosaic model | describes how a plasma membrane is a fluid structure with a variety of proteins embedded or attached to a double layer of phospholipids | |
| 41457414 | integral protein | a transmembrane protein that penetrates the hydrophobic core of the lipid bilayer | |
| 41457415 | peripheral protein | a type of membrane protein that is not embedded in the lipid bilayer at all, but rather, loosely bound to the surface of the membrane | |
| 41457416 | glycolipid | short, branched chains of fewer than 15 sugar units covalently bonded to a lipid in the plasma membrane | |
| 41457417 | glycoprotein | short, branched chains of sugar units covalently bonded to a protein in the plasma membrane | |
| 41457418 | transport protein | a channel or carrier protein that allows hydrophilic substances through the plasma membrane | |
| 41457419 | aquaporin | a channel protein that transports water molecules through the plasma membrane | |
| 41457420 | diffusion | the spontaneous movement of a substance down its concentration gradient, from a region where it is more concentrated to a region where it is less concentrated | |
| 41457421 | concentration gradient | the region along which the density of a chemical substance increases or decreases | |
| 41457422 | passive transport | the diffusion of a substance across a biological membrane where the cell does not have to expend energy to make it happen | |
| 41457423 | osmosis | the diffusion of water across a selectively permeable membrane | |
| 41457424 | tonicity | the ability of a solution to cause a cell to gain or lose water | |
| 41457425 | isotonic | having the same solute concentration as another solution, thus having no effect on passage of water into or out of the cell | |
| 41457426 | hypertonic | in comparing two solutions, referring to the one with a greater solute concentration, which, when surrounding a cell, will cause the cell to lose water | |
| 41457427 | hypotonic | in comparing two solutions, referring to the one with a lower solute concentration, which, when surrounding a cell, will cause the cell to take up water | |
| 41457428 | osmoregulation | control of solute concentrations and water balance by a cell or organism | |
| 41457429 | turgid | swollen, or distended, as in plant cells | |
| 41457430 | flaccid | lacking in stiffness or firmness, as in plant cells; limp | |
| 41457431 | plasmolysis | a phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall | |
| 41457432 | facilitated diffusion | the passive diffusion of polar molecules and ions through the plasma membrane with the help of transport proteins | |
| 41457433 | ion channel | a transmembrane protein that allows a specific ion to flow across the cell membrane down its concentration gradient | |
| 41457434 | gated channel | a transmembrane protein in a cell membrane that opens or closes in response to a particular stimulus | |
| 41457435 | active transport | the movement of a substance across a cell membrane, with an expenditure of energy, against its concentration or electrochemical gradient | |
| 41457436 | sodium-potassium pump | a transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell | |
| 41457437 | membrane potential | the charge difference between a cell's cytosol and the extracellular fluid, due to the differential distribution of ions | |
| 41457438 | electrochemical gradient | the diffusion gradient of an ion, which is affected by both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential | |
| 41457439 | electrogenic pump | an ion transport protein that generates voltage across a membrane | |
| 41457440 | proton pump | an active transport protein in a cell membrane that uses ATP to transport hydrogen ions out of a cell against their concentration gradient, generating a membrane potential in the process | |
| 41457441 | cotransport | the coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient | |
| 41457442 | exocytosis | the cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane | |
| 41457443 | endocytosis | cellular uptake of biological molecules and particulate matter via formation of new vesicles from the plasma membrane | |
| 41457444 | phagocytosis | a type of endocytosis in which large particulate substances are taken up by a cell | |
| 41457445 | pinocytosis | a type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes | |
| 41457446 | receptor-mediated endocytosis | the movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances | |
| 41457447 | ligand | a molecule that binds specifically to another molecule, usually a larger one |