| A | B |
|---|
| receptor proteins | proteins found embedded in the cell membrane that send signals to the inside of the cell |
| diffusion | movement of substance from a region of high concentration to a region of lower concentration, uses kinetic energy of the molecules |
| osmosis | diffusion of water |
| selective transport | movement of specific molecules by means of protein channels and pumps |
| facilitated diffusion | form of selective transport that can only move molecules from high to low concentration using carrier proteins |
| active transport | movement of molecules (usually against the concentration gradient) that requires ATP (cell's energy), work is done, molecules can be concentrated against the gradient |
| sodium-potassium pump | channels which move sodium ions out of the cell and potassium ions into the cell |
| proton pump | protein pumps that move hydrogen protons out of the cell to balance pH (acidity) or help generate ATP |
| endocytosis | process of the cell engulfing large particles to bring them inside the cell |
| exocytosis | wastes or secretions expelled from the cell using small sacs |
| metabolism | chemical reactions that occur in a cell |
| ATP | energy molecule of the cell that is used for metabolism |
| Homeostasis | the stable internal condition of a living thing |
| hypertonic (solution) | when solute molecules outside the cell are higher in concentration than inside the cell (cytosol) water moves out |
| hypotonic (solution) | when concentration of solutes inside the cell are higher than outside the cell (cytosol) water moves in |
| isotonic (solution) | when solutes inside and outside the cell are equal |
| contractile vacuoles | organelles used by unicellular organisms to pump excess water out of the cell (requires energy) |
| turgor pressure | pressure excerted by water in plant cells against the cell wall |
| wilting | a loss of turgor pressure due to a loss of water in the plant cells |
| plasmolysis | loss of water from the cytosol causing shrinking orcollapse of the cell |
| cytolysis | expansion of cell volume due to diffusion of water in the cell, may cause cell to burst |
| carrier proteins | peripheral or imbedded proteins that function to move molecules across the cell membrane |
| sodium-potassium pump | a carrier protein that facillitates the movement of sodium and potassium across the membrane ( ATP is needed, work is done) |
| Endocytosis | Formation of a vesicel to ingest macromolecules, large particles, other cells (requires energy) |
| Exocytosis | opposite of endocytosis, formaton of a vessicle to move out macromolecules from the cell (requires energy) |
| pinocytosis | endocytosis involving transport of solutes and fluids |
| phagocytosis | endocystosis involving the inport of large particles or whole cells |
