Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Ap Biology Ch. 7
Membrane Structure and Function
| Question | Answer |
|---|---|
| selective permeability | A property of biological membranes that allows some substances to cross more easily than others |
| amphipathic molecule | a molecule that has both a hydrophilic region and a hydrophobi region |
| fluid mosaic model | The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individual protein molecules drifting laterally in a fluid bilayer of phospholipids |
| integral protein | typically a transmembrane protein with hydrophobic regions that completely spans the hydrophobic interior of the membrane |
| peripheral protein | A protein appendage losely bound to the surface of a membrane and not embedded in the lipid bilayer |
| glycolipid | A lipid covalently bonded to a carbohydrate |
| glycoprotein | A protein covalently bonded to a carbohydrate |
| transport protein | A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane |
| 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) |
| diffusion | The spontaneous tendancy of a substanc to move down its concentration gradient from a more concentrated to a less concentrated area |
| concentration gradient | increase or decrease in density of chemical substance in an area.Cells often maintain concentration gradients of ions across their membranes.When gradient exists ions or other chemical substances tend move from more concentrated to less concentrated area |
| passive transport | The diffusion of a substance across a biological membrane. |
| osmosis | The diffusion of water across a selectively permiable membrane |
| tonicity | The ability of a solution to cause a cell within it to gain or loose water |
| isotonic | Having the same solute concentration as another solution |
| hypotonic | In comparing two solutions, referring to the one with a lower solute concentration |
| hypertonic | In comparing two solutions, referring to the one with a greater solute concentration |
| osmoregulation | How organisms regulate solute concentrations and balance the gain and loss of water |
| turgid | Very firm. A walled cell becomes turgid if it has a greater solute concentration than its surroundings, resulting in the entry of water |
| flaccid | Limp. A walled cell is flaccid in surroundings where there is no tendency for water to enter |
| facilitated diffusion | The spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients |
| ion channel | Protein channel in a cell membrane that allows passage of a specific ion down its concentration gradient |
| gated channel | A protein channel in a cell membrane that opens or closes in response to a particular stimulus |
| active transport | The movement of a substance across a biological membrane against its concentration gradient or electrochemical gradient with the help of energy input and specific transport proteins |
| sodium-potassium pump | A special transport protein in the plasma membrane of animal cells that transport sodium out of the cell and potassium into the cell against their concentration gradients |
| mebrane potential | charge difference between a cell's cytoplasm and the extracellular fluid due to the differential distribution of ions. Membrane potential effects the potential of excitable cells and the transmembrane movement of all charged substances |
| electrochemical gradient | diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion and across a membrane and its tendency to move relative to the membrane potential |
| electrogenic pump | an ion transport protein that generates voltage across a membrane |
| proton pump | An active transport mechanism in cell membranes that uses ATP to force hydrogen ions out of a cell, generating a membrane potential in the process |
| cotransport | The coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient |
| exocytosis | The cellular secetion of macromolecules by the fushion of vesicles with the plasma membrane |
| 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 |
| ligand | a molecule that binds specifically to a receptor site of another molecule |
| phagocytosis | a type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells |
| pinocytosis | A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes |
| receptor-mediated endocytosis | movement of specific molecules into a cell by the inward budding of membranous vesicles contain proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances |
Created by:
gnomealot
Popular Biology sets