Chapter 6 Key Terms central vacuole centriole centrosome chromatin chromosome cilium contractile vacuole crista electron microscope (EM) endoplasmic reticulum (ER) extracellular matrix (ECM) flagellum food vacuole gap junction granum intermediate filament light microscope (LM) lysosome microfilament microtubule mitochondrial matrix nucleoid nucleolus nucleus phagocytosis plasmodesma pseudopodium scanning electron microscope (SEM) stroma thylakoid tight junction transmission electron microscope (TEM) Concepts How We Study Cells 1. Know the brief history of cell study, the cell theory, and the scientists. 6 2. Know the different functions of the light microscope, transmission electron microscope, and scanning electron microscope. pg96 Light Microscope(LMs): Refracts(bends) the visible light passing through a specimen such that a projected image is magnified. Transmission electron microscope: (TEM) A beam of electrons is passed through a thin section of a specimen stained with atoms of heavy metals , and electromagnets, acting as lenses, focus the image onto a screen or film. Electron Microscope(EM) : Focuses a beam of electrons through the specimen. The short wavelength of the electron beam allows a resolution of about 2 nanometers ( a hundred times greater than that of the light microscope.
Scanning Electron Microscope(SEM): an electron beam scans the surface of a specimen usually coated with a thin gold film, exciting electrons from the specimen, which are detected and translated into an image on a video screen. ( image appears 3-D)> The Nucleus and Ribosomes 3. Know the structure and function of the nucleus, including the role of the pore complex. pg102 The nucleus contains most of the genes in the eukaryotic cell. (might want to look up nuclear envelope, nucleolus, chromatin,and nuclear lamina.) Pore Complex: An intricate protein structure that lines each pore and regulates the entry and exit of certain macromolecules and particles. ( Refer to page 103 Figure 6.10) 4. Know the structure and function of ribosomes. Distinguish between free and bound ribosomes in terms of location and function. Pg 102 Ribosomes , particles made of ribosomal RNA and protein, are the organelles that carry out protein synthesis. (structure: non membranous organlle free in cytoplasm or bound to rough ER or nuclear envelope.) Free Bound: Suspended in the cytosol. Most of the proteins made on free ribosomes function within the cytosol ( i.e. : enzymes that catalyze the first steps of sugar breakdown.) Bound: Attached to the outside of the endoplasmic reticulum or nuclear envelope. (generally make proteins that are destined either for insertion into membranes, for packaging within certain organelles such as lysosomes or for export from the cell (secretion) (i.e. : cells of the pancreas have high proportion of them.) The Endomembrane System 5. Compare the structure and functions of smooth and rough ER. pg 104/105 Smooth ER: Lack ribosomes. Important to synthesis of lipids(fats) , including oils,
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