| A | B |
|---|
| The Cell Theory | A. Cells are the structural and functional unit of life B. Cells are produced from preexisting cells C. Cells are the smalles structural units of life |
| Cell Membrane | forms the outer boundary of the cell; isolates the cytoplasm |
| phospholipid bilayer | phospholipid molecules in a double layer; (nonpolar tails face towards eachother) |
| membrane proteins | found in and on the surfaces of membrane; act as channels, receptors, and markers |
| Major Structural Components | 1. phospholipid bilayer 2. membrane proteins |
| cytology | study of cells |
| selective Permeability | cell membrane characteristic, allows the passage of some materials and not others |
| passive transport | 1. diffusion 2. Osmosis and Bulk flow 3. Filtration 4. Facilitated diffusion |
| diffusion | movement of solute particles from high to low concentration |
| Osmosis and Bulk Flow | diffusion of water molecules across the cell membrane |
| Filtration | movement of solution across a membrane whose pores restrict the passage of the solutes on the basis of size |
| Facilitated Diffusion | diffusion of a solute across a membrane via a protein carrier b/c solute is too large to fit through a channel protein |
| Active Transport and the Concentration Gradient | movement of substances across the cell membrane w/ the expenditure of cell energy. Needed to move substances against the concentration gradient |
| Ion Pumps | move ions in and out of cell membrane through a protein channel to maintain high intracellular K+ and high extracellular Na+ |
| endocytosis and Exocytosis | materials packaged in a vesicle and moved into "endo" or out of "exo" the cell |
| endocytosis includes... | pinocytosis - "cell drinking" |
| exocytosis includes.... | phagocytosis - "cell eating" |
| Cytoplasm | general term for all material inside cell (except nucleus) contains more protein than extracellular fluid |
| cytosol | intracellular fluid, has high K+ and low Na+ and other dissolved substances |
| inclusions | insoluable material suspended in cytosol, usually stored nutrients |
| organelles | "little organ" structures that perform specific functions within cells; size, number and type vary depending on cell |
| Structure of Gap Junctions | holds cells together by channel proteins |
| Function of Gap Junctions | allows movement of small ions, needed for cells hat coordinate activities |
| Structure of Tight Junctions | holds cells together by partial fusion of cell membranes |
| Function of Tight Junctions | prevents passage of extracellular substances in between adjacent cells; common on cells w/ exposed surfaces |
| Structure of Intermediate Junctions | holds cells together by an intercellular cement, reinforced by protein filaments inside cells |
| Function of Intermediate Junctions | Stabilizes and strengthens cell shape |
| Desmosomes | "binding bodies" |
| Structure of Desmosomes | holds cells together by an intercellular cement reinforced by protein filaments inside and between the cells |
| Function of Desmosomes | Connects cells to extracellular structures; common in cells that resist stretching and twisting -- skin |
| Structure of Junctional Complexes | tight junction, intermediate junction, and desmosome junction holding cells together |
| Function of Junctional Complexes | Forms the strongest connection between cells, found in digestive tract and other passageways |
