Biology 7-3
Order by
20 terms
Terms | Definitions |
|---|---|
 cell membrane | the outer edges of a cell, also called the plasma membrane, that is thin and flexible. it regulates what enters and leaves the cell and also provides protection and support. |
| lipid bilayer | a double-layered sheet that makes up the cell membrane |
| fluid mosaic model | so many kinds of molecules are in cell membranes that they make up a fluid mosaic of proteins, lipids and carbohydrates |
| cell walls | the main function of the cell wall is to provide support and protection for the cell |
| diffusion through cell membrane | the movement of dissolved molecules from the liquid on one side of the membrane to the liquid on the other side |
| concentration | the mass of solute in a given volume of solution, or mass/volume |
| diffusion in a solution | the particles in a solution tend to move from an area where they are more concentrated to an area where they are less concentrated |
| equilibrium | when particles are equally distributed throughout a solution |
| DIFFUSION NOTE: | Because diffusion depends upon random particle movements, substances diffuse across membranes without requiring the cell to use energy. |
| Osmosis | the diffusion of water through a selectively permeable membrane |
| isotonic | "same strength", when the fluid on one side of a cell wall and the other side is equally mixed |
| hypertonic | "above strength" more concentrated on one side than the other |
| hypotonic | "below strength" less concentrated on one side than the other (see photo on page 186) |
| Osmotic pressure | occurs on the hypertonic side of a selectively permeable membrane. If it builds too much the cell will explode. |
| Facilitated Diffusion | molecules that cannot pass through the cell wall on their own move through protein channels instead. Glucose moves through blood in this way. |
| active transport | requires energy o move moelcules against a concentration difference. small "pumps" are found in the membrane itself |
| endocytosis | process of taking material into the cell by infoldings, or pockets of the cell membrane |
| phagocytosis | extensions of cytoplasm surround a particle and package it in a food vacuole. The cell then engulfs it. (active transport) |
| pinocytosis | cells that take up liquid from the surrounding environment |
| exocytosis | the membrane of a vacuole surrounding the material fuses with the cell membrane, forcing the contents out of the cell - for example, moving water by means of a contractile vacuole |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.