Biology Chapter 7
Terms : Hide Images [1]
39458641 | hypotonic | less solute concentration than another solution | |
39458642 | amphipathic | has hydrophilic and hydrophobic region | |
39458643 | Davson-Danielli model | lipid bilayer model coated on both sides with hydrophilic proteins (sandwich model) | |
39458644 | fluid mosaic model | model of membrane as a mosaic of amphipathic protein molecules bobbing in fluid bilayer of phospholipids | |
39458645 | integral proteins | embedded in bilayer's core | |
39458646 | peripheral proteins | loosely bound to membrane surface | |
39458647 | glycolipid | carbohydrates proteins covalently bonded to lipids | |
39458648 | glycoprotein | carbohydrates covalently bonded to proteins | |
39458649 | channel protein | transport protein that functions by having a hydrophilic channel that certain molecules use as a tunnel through the membrane | |
39458650 | aquaporin | channel protein that specifically facilitates osmosis | |
39458651 | carrier protein | transport protein that holds onto passengers and change conformation to shuttle them across membrane | |
39458652 | concentration gradient | path traveled in order to balance the concentration of a substance across a space | |
39458653 | tonicity | solution's ability to to cause a cell to gain or lose water | |
39458654 | isotonic | having same solute concentration as another solution | |
39458655 | hypertonic | solution with higher solute concentration | |
39458656 | osmoregulation | control of water balance | |
39458657 | gated channel | ion channel protein that opens and closes by stimulus | |
39458658 | electrochemical gradient | combination of chemical and electrical forces acting on an ion | |
39458659 | membrane potential | energy source affecting traffic of all charged substances across a membrance | |
39458660 | electrogenic pump | transport proteins that generate voltage across a membrane | |
40393332 | selective permeability | the plasma membrane exhibits ________ ________; it allows some substances to cross it more easily than others | |
40393333 | freeze fracture | a method of preparing cells for electron microscopy is called _____ ______, which splits a membrane along the middle of the phospholipid bilayer | |
40393334 | temperature buffer | cholesterol is a _______ _________ for the membrane; it resists changes in membrane fluidity that can be caused by changes in temperature | |
40393335 | transport protein | some hydrophilic substances can avoid the lipid bilayer by passing through this | |
40393336 | turgid | _____ is a healthy state for most plant cells, where the cell wall exerts pressure to stop further intake of water | |
40393337 | flaccid | if a plant's cells and their surroundings are isotonic, there is no net tendency for water to enter, and the cells become _______ | |
40393338 | 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 | |
40393339 | facilitated diffusion | many polar molecules and ions impeded by the lipid bilayer of a membrane diffuse passively with the help of transport proteins that span the membrane | |
40393340 | ion channels; gated channels | ____ ________ allow certaion ions to pass and they can function as _______ _____, where a stimulus causes them to open or close | |
40393341 | active transport | to pump a molecule across a membrane agaist its gradient requires work; the cell must expend energy | |
40393342 | sodium-potassium pump | a ______-_______ _____ exchanges sodium (Na+) for potassium (K+) across the plasma membrane of animal cells | |
40393343 | voltages | all cells have _______ across their plasma membranes | |
40393344 | membrane potential | the _______ ________ is an energy source that affects the traffic of all charged substances across the membrane | |
40393345 | proton pump | the main electrogenic pump in plants, fungi and bacteria is a _______ _________, which actively transports hydrogen ions out of the cell | |
40393346 | cotransport | a single ATP-powered pump that transports a specific solute can indirectly drive the active transport of several other solutes in a mechanism called _________ | |
40393347 | endocytosis | the cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane | |
40393348 | exocytosis | the cell secretes macromolecules by the fusion of vesicles with the plasma membrane |