| A | B |
|---|
| Light Microscope (LMs) | visible light passed through specimen and then through glass lenses |
| Resolving Power | measure of the clarity of the image |
| Magnification | ratio of an object's image to its real size |
| Robert Hooke | discovered cells in 1665 |
| Organelles | subcellular structures |
| Electron Microscope (EM) | a beam of electrons focused through the specimen or onto its surface |
| Cell Ultrastructure | cell's anatomy as revealed by an electron microscope |
| Transmission electron microscope | used to study internal ultrastructure of cell; aims an electron beam through a thin section of the specimen |
| Scanning electron microscope | useful for detailed study of the surface of a specimen; electron beam scans sample surface |
| Cytology | study of cells |
| Biochemistry | study of the molecules and chemical processes of metabolism |
| Cell Fractionation | take cells apart, separating the major organelles so that their functions can be studied |
| Centrifuge | instrument used to fractionate cells by spinning them at various speeds |
| homogenization | disruption of cells; breaking cells apart without damaging organelles |
| pellet | larger, heavier structures at the bottom of a centrifuge tube |
| supernatant | smaller, lighter parts suspended in liquid above pellet in centrifuge tube |
| cytosol | semifluid substance in which organelles are found |
| plasma membrane | cell membrane; selective barrier that allows sufficient passage of O2, nutrients, and waste |
| prokaryotic cell | no membrane bound organelles; DNA concentrated in nucleoid |
| nucleoid | region of DNA concentration in prokaryotic cells |
| eukaryotic cell | cell with a true nucleus surrounded by a nuclear envelope |
| cytoplasm | entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane |
| nucleus | contains most of the cell's genetic information; |
| nuclear envelope | double plasma membrane; surrounds nucleus |
| pore complex | intricate protein structure lining pores of the nuclear envelope; regulates entry and exit of certain large macromolecules |
| nuclear lamina | netlike array of protein filaments that maintain the shape of the nucleus |
| nuclear matrix | framework of fibers extending throughout the nuclear interior |
| chromatin | DNA organized with proteins into fibrous material |
| chromosomes | chromatin coiled into thick structures |
| nulceolus | synthesis site of rRNA |
| ribosomes | composed of rRNA and protiens; carry out protein synthesis |
| free ribosomes | suspended in cytosol |
| bound ribosomes | attached to outside of ER or nuclear envelope |
| endomembrane system | system of membranes connected either through direct physical continuity or by transfer of vessicles |
| vessicle | membrane segments used as transport |
| ER | accounts for more than 1/2 the total membrane in eukaryotic cells; network of tubules and cisternae |
| cisternae | sacs within the ER and Golgi apparatus |
| cisternal space | internal compartment of the ER |
| smooth ER | cytoplasmic surface lacks ribosomes |
| rough ER | cytoplasmic surface has ribosomes |
| glycoproteins | proteins that are covalently bonded to carbohydrates |
| transitional ER | area of the ER from which transport vesicles bud |
| transport vesicles | membrane-bound vesicle that transits from one area of the cell to another |
| Golgi apparatus | organelle which modifies, stores, then ships products of the ER |
| lysosome | sac of hydrolytic enzymes that digests macromolecules |
| phagocytosis | process by which protists eat by engulfing smaller organisms or food particles |
| autophagy | process of lysosomes using enzymes to recycle the cell's own organic material |
| food vacuoles | membrane bound sac that stores food particles |
| contractile vacuole | vacuole that pumps excess water out of the cell |
| tonoplast | membrane that surrounds the central vacuole in plants |
| mitochondria | site of cellular respiration |
| chloroplast | site of photosynthesis; plastid that contains chlorophyll, enzymes |
| cristae | outer folded membrane of the mitochondria |
| mitochondrial matrix | inner compartment of mitochondria containing enzymes, mitochondrial DNA, & ribosomes |
| plastid | fmily of closely related plant organelles |
| amyloplasts | plastid that stores starch |
| chromoplast | plastid that stores pigments |
| thylakoids | membranous system of flattened sacs inside the chloroplast |
| granum | stacks of thylakoids |
| stroma | fluid outside the grana |
| peroxisome | specialized metabolic compartment containing enzymes that transfer H2 from various substrates to O2, producing H2O2 |
| cytoskeleton | a network of fibers extending throughout the cytoplasm |
| microtubules | hollow rods that shape and support the cell, serve as tracks along which organelles equipped with motor molecules can move |
| centrosome | a region of microtubles near the nucleus, function as compression-resisting girders of the cytoskeleton |
| centrioles | composed of 9 sets of triplet microtubules arranged in a ring |
| flagella | single, long locomotor appendage |
| cilia | locomotor appendages, usually in large numbers, short |
| basal body | attachment site of ciium or flagellum |
| dynein | large protein of motor molecules are made |
| actin | globular protein of which microfilaments are made |
| microfilaments | solid rods, also called actin filaments |
| myosin | protein that acts as a motor molecule by means of projection arms that walk along actin filaments |
| pseudopodia | "false foot", protrusion from the cell that extends and contracts in order to move the cell |
| cytoplasmic streaming | cicular flow of cytoplasm with cell |
| cell wall | exterior layer of plant, fungal, and some protists; protects, shapes and prevents excessive water uptake |
| primary cell wall | in young plants; relatively thin and flexible |
| middle lamella | thin layer rich in pectins that separates primary wall of adjacent cells |
| secondary cell wall | area between primary wall and cell membrane; often deposited in several laminated layers; strong, durable matrix |
| ECM | found externally around animal cells; extracelluar matrix; mainly glycoproteins; regulates cell behavior; communicates with cell via integrins |
| collagen | glycoprotein which forms strong fibers outside cells; accounts for half the protein in human body |
| proteoglycans | glycoproteins rich in carbohydrates; form large complexes |
| integrins | receptor proteins that bind fibronectins to plasma membrane |
| plasmodesmata | channels in plant cell walls |
| intercellular junctions | common in epithelial tissue (internal body surface lining) |
| tight junction | occur when membranes of neighboring cells fuse, forming continuous belts around cells; prevent leakage of ECF across layers of epithelial cells |
| desmonosome | (AKA anchoring junction) fasten cells together into strong sheets |
| gap junctions | (AKA communication junctions) provide cytoplasmic channels between adjacent animal cells |
