Campbell 7e Ch7
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| 580504583 | active transport | The movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins. | 0 | |
| 580504584 | amphipathic molecule | A molecule that has both a hydrophilic region and a hydrophobic region. | 1 | |
| 580504585 | aquaporin | A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane (osmosis). | 2 | |
| 580504586 | bulk transport | Mechanism of large molecule (proteins, polysaccharides, particles) crossing membrane involving vesicles (exocytosis, endocytosis) bk | 3 | |
| 580504587 | concentration gradient | An increase or decrease in the density of a chemical substance in an area. Cells often maintain ___ of ions across their membranes. When a ___exists, the ions or other chemical substances involved tend to move from where they are more ___to where they are less ___. | 4 | |
| 580504588 | contractile vacuole | A membranous sac that helps move excess water out of the cell. | 5 | |
| 580504589 | cotransport | The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient. | 6 | |
| 580504590 | diffusion | The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area. | 7 | |
| 580504591 | electrochemical gradient | The diffusion gradient of an ion; a type of potential energy that accounts for the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential. | 8 | |
| 580504592 | electrogenic pump | An ion transport protein generating voltage across the membrane. | 9 | |
| 580504593 | endocytosis | The cellular uptake of macromolecules and particulate substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle. | 10 | |
| 580504594 | exocytosis | The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane. | 11 | |
| 580504595 | facilitated diffusion | The spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients. | 12 | |
| 580504596 | flaccid | Limp. Walled cells are ___in isotonic surroundings, where there is no tendency for water to enter. | 13 | |
| 580504597 | fluid mosaic model | The currently accepted model of cell membrane structure, which envisions the membrane as a ___ of individually inserted protein molecules drifting laterally in a __ bilayer of phospholipids. | 14 | |
| 580504598 | gated channel | A protein channel in a cell membrane that opens or closes in response to a particular stimulus. | 15 | |
| 580504599 | glycolipid | A lipid covalently attached to a carbohydrate. | 16 | |
| 580504600 | glycoprotein | A protein covalently attached to a carbohydrate. | 17 | |
| 580504601 | hypertonic | In comparing two solutions, referring to the one with a greater solute concentration. | 18 | |
| 580504602 | hypotonic solution | In comparing two solutions, the one with a lower solute concentration. | 19 | |
| 580504603 | integral protein | Typically transmembrane proteins with hydrophobic regions that completely span the hydrophobic interior of the membrane. | 20 | |
| 580504604 | isotonic | Having the same solute concentration as another solution. | 21 | |
| 580504605 | ligand | A molecule that binds specifically to a receptor site of another molecule. | 22 | |
| 580504606 | membrane potential | The charge difference between the cytoplasm and extracellular fluid in all cells, due to the differential distribution of ions; affects the activity of excitable cells and the transmembrane movement of all charged substances. | 23 | |
| 580504607 | osmoregulation | The control of water balance in organisms living in hypertonic, hypotonic, or terrestrial environments. | 24 | |
| 580504608 | osmosis | The diffusion of water across a selectively permeable membrane. | 25 | |
| 580504609 | passive transport | The diffusion of a substance across a biological membrane. | 26 | |
| 580504610 | peripheral protein | Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer. | 27 | |
| 580504611 | phagocytosis | A type of endocytosis involving large, particulate substances. | 28 | |
| 580504612 | pinocytosis | A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes. | 29 | |
| 580504613 | plasmolysis | A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall when the cell loses water to a hypertonic environment. | 30 | |
| 580504614 | proton pump | An active transport mechanism in cell membranes that consumes ATP to force hydrogen ions out of a cell and, in the process, generates a membrane potential. | 31 | |
| 580504615 | 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. | 32 | |
| 580504616 | selective permeability | A property of biological membranes that allows some substances to cross more easily than others. | 33 | |
| 580504617 | 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. | 34 | |
| 580504618 | tonicity | The ability of a solution to cause a cell to gain or lose water. Dependent upon solute concentration and membrane permeability. Bk | 35 | |
| 580504619 | transport protein | A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane. | 36 | |
| 580504620 | turgid | Firm. Walled cells become ____ as a result of the entry of water from a hypotonic environment. | 37 |
