| Question |
Answer |
| passive transport | process by which some substances can cross the cell membrane without any input of energy by the cell |
| diffusion | movement of molecules from an area of higher concentration to an area of lower concentration |
| concentration gradient | difference in the concentration of molecules across a distance |
| equilibrium | concentration of molecules is the same throughout the space the molecules occupy |
| simple diffusion | diffusion across a membrane that only allows certain molecules to pass through the membrane |
| osmosis | process by which water molecules diffuse across a cell membrane from an area of higher concentration to an area of lower concentration |
| hypotonic | describes a solution whose solute concentration is lower than the solute concentration inside a cell |
| hypertonic | describes a solution whose solute concentration is higher than the solute concentration inside a cell |
| isotonic | describes a solution whose solute concentration is equal to the solute concentration inside a cell |
| contractile vacuoles | organelles that remove water by collecting the excess water and then contracting to pump out the water |
| turgor pressure | pressure that water molecules exert against the cell wall |
| plasmolysis | condition in which cells shrink away from the cell walls, and turgor pressure is lost |
| cytolysis | condition in which a hypotonic environment causes water to diffuse into the cell, making it swell and eventually burst |
| facilitated diffusion | type of passive transport in which molecules that cannot readily diffuse through cell membranes are assisted by carrier proteins; thus ~ facilitated |
| carrier proteins | specific proteins in the membrane that assist the movement of molecules in facilitated diffusion |
| ion channels | type of membrane protein involved in passive transport - diffusion through ion channels |
| active transport | movement of materials from an area of lower concentration to an area of higher concentration; UP concentration gradient; REQUIRES cell to expend ENERGY |
| sodium-potassium pump | transports Na+ ions and K+ ions up their concentration gradients |
| endocytosis | process by which cells ingest external fluid, macromolecules, and large particles, including other cells |
| pinocytosis | involves transport of solutes or liquids: DRINK |
| phagocytosis | movement of large particles or whole cells |
| phagocytes | cells that allow lysosomes to fuse with the vesicles that contain the ingested bacteria and viruses |
| vesicle | pouch pinched off from the cell membrane, becoming a membrane bound organelle |
| exocytosis | the process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out of the cell |
Science Vocab 147928
