| A | B |
|---|
| light microscopes (LMs) | uses visible light as viewing medium |
| resolving power | measure of clarity of image |
| organelles | subcellular structures |
| electron microscope (EM) | uses beam of electrons as viewing medium |
| transmission electron microscope (TEM) | aime electron beam through thin section of specimen, use electromagmet as lenses to focus and magnify |
| scanning electron microscope (SEM) | used for detailed study of surface of specimen which is coated in gold, great depth of field, 3-D image |
| cell fractionation | separating major organelles |
| ultracentrifuges | 80,000 rpm; 500,000 g |
| prokaryotic cell | no nucleus |
| nucleoid | concentrated region fo DNA in prokaryotes, no membrane |
| cytoplasm | region between the nucleus and cell membrane |
| cytosol | semifluid medium of cytoplasm |
| plasma membrane | boundary of cell, selective membrane |
| nucleus | contains most of the genes that control eukaryotes |
| nuclear lamina | netlike array of protein filaments that maintain shape of nucleus |
| chromatin | within the nucleus DNA arranges with proteins into chromatin |
| chromosomes | formed from chromatin during division |
| nucleolus | where components fo ribosomes are synthesized and assembeled |
| ribosomes | sites where the cell makes protein |
| endoplasmic reticulum (ER) | network of cisternae, smooth and rough |
| glycoproteins | proteins that are covalently bonded to carbs., most secretory proteins |
| transport vesicles | vesicles in transit |
| golgi apparatus | center of manufacturing, sorting, and shipping |
| lysosome | sac of hydrolytic enzymes that the cell uses to digest macromolecules |
| phagocytosis | cell eating |
| food vacuoles | formed by phagocytsis |
| contractile vacuoles | pump excess water out of the cell |
| central vacuole (enclosed by tonoplast) | usually found in mature plants |
| mitochondria | sites of cellular resporation (catabolic process that generates ATP by extracting energy form sugars, fats, and other fules with the help of oxygen) |
| chloroplasts | sites of photosynthesis |
| cristae | infoldings in membrane |
| mitochondrial matrix | second compartment, inclosed by inner membrane |
| plastids | family of plant organelles |
| thylakoids | flattened sacs inside chloroplasts |
| grana | form from thylakoids arranged into poker chip-like structures |
| stroma | fluid outside the thylakoids |
| peroxisome | specialized metabolic compartment, single membrane |
| cytoskeleton | network of fibers through the cytoplasm |
| microtubules | thickest, grow out of centrosomes (within which are a pair of centrioles), responsible for movements of cilia and flagella (these use the motor molecule dynein) |
| microfilaments | also called actin filaments, built from globular protein actin and myosin, responsible for the movements of pseudopodia and cytoplasmic streaming |
| intermediate filaments | bear tension |
| cell wall | in plants, protects, maintains shape, and prevents excessive uptake of water, composed of primary cell wall, middle lamella, and secondary cell wall |
| extracellular matrix (ECM) | in animal cells, composed of collagen embedded in proteoglycans, connected to cell by fibronectins (which bind to receptor proteins called integrins) |
| plasmodesmata | channels in cell walls |
| 3 types of intercellular junctions | tight, desmosomes, gap |
| selective permeability | allows some substances to cross |
| amphipathic | both hydrophilic and hydrophobic |
| fluid mosaic model | membrane is a mosaic of protein molecules in a fluid phospholipid bilayer |
| integral protein | hydrophobic regions completley span the membrane |
| peripheral proteins | appendages loosely bound to the surface of the membrane, often to integral proteins |
| transport proteins | span membrane, move specific substances across |
| diffusion | tendency for molecules to spread out |
| concentration gradient | all substances will diffuse down this |
| passive transport | diffusion across a biological membrane |
| hypertonic | solution with the higher concentration, relatively |
| hypotonic | solution with a relatively lower concentration |
| isotonic | solutions are of euqal solute concentration |
| osmosis | diffusion of water across a membrane |
| osmoregulation | control of water balance |
| turgid | very firm |
| flaccid | limp |
| plasmolysis | as plant cell shrivels its membrane pulls away from its wall |
| facilitated diffusion | diffusion with the help of transport proteins |
| gated channels | stimulus causes proteins to open or close |
| active transport | uphill, required work |
| Na-K pump | exchangess Na for K in animal cells |
| membrane potential | voltage across a membrane |
| electorchemical gradient | combonation of forces acting on an ion |
| electorgenic pump | a transport protein that generates coltage across a membrane |
| proton pump | main electrogenic pump of plants, transports H+ out of cell |
| cotransport | when an ATP powered pump indirectly dirves the active transport of other solutes |
| exocytosis | secretion of macromolecules |
| receptor-mediated endocytosis | very specific, receptors bind to extracellular lingands |
