Chapter 6Slide 2Slide 3Slide 4MicroscopySlide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Isolating Organelles by Cell FractionationSlide 14Slide 15Slide 16Slide 17Slide 18Comparing Prokaryotic and Eukaryotic CellsSlide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26A Panoramic View of the Eukaryotic CellSlide 28Slide 29Slide 30Slide 31The Nucleus: Genetic Library of the CellSlide 33Ribosomes: Protein Factories in the CellSlide 35Slide 36The Endoplasmic Reticulum: Biosynthetic FactorySlide 38Slide 39Functions of Smooth ERFunctions of Rough ERThe Golgi Apparatus: Shipping and Receiving CenterSlide 43Slide 44Lysosomes: Digestive CompartmentsSlide 46Slide 47Vacuoles: Diverse Maintenance CompartmentsSlide 49Slide 50The Endomembrane System: A ReviewSlide 52Slide 53Mitochondria: Chemical Energy ConversionSlide 55Chloroplasts: Capture of Light EnergySlide 57Slide 58Peroxisomes: OxidationSlide 60Slide 61Roles of the Cytoskeleton: Support, Motility, and RegulationSlide 63Components of the CytoskeletonSlide 65MicrotubulesCentrosomes and CentriolesSlide 68Cilia and FlagellaSlide 70Slide 71Slide 72Slide 73Slide 74Slide 75Microfilaments (Actin Filaments)Slide 77Slide 78Slide 79Slide 80Intermediate FilamentsSlide 82Cell Walls of PlantsSlide 84The Extracellular Matrix (ECM) of Animal CellsSlide 86Slide 87Intercellular JunctionsPlants: PlasmodesmataAnimals: Tight Junctions, Desmosomes, and Gap JunctionsSlide 91The Cell: A Living Unit Greater Than the Sum of Its PartsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsPowerPoint Lectures for Biology, Seventh EditionNeil Campbell and Jane ReeceLectures by Chris RomeroChapter 6Chapter 6A Tour of the CellCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsOverview: The Importance of Cells•All organisms are made of cells•The cell is the simplest collection of matter that can liveCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Cell structure is correlated to cellular function10 µm Figure 6.1Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Concept 6.1: To study cells, biologists use microscopes and the tools of biochemistryCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsMicroscopy•Scientists use microscopes to visualize cells too small to see with the naked eyeCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Light microscopes (LMs)–Pass visible light through a specimen–Magnify cellular structures with lensesCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Different types of microscopes–Can be used to visualize different sized cellular structuresUnaided eye1 m0.1 nm10 m0.1 m1 cm1 mm100 µm10 µ m1 µ m100 nm10 nm1 nmLength of somenerve and muscle cellsChicken eggFrog eggMost plant and Animal cellsSmallest bacteriaVirusesRibosomesProteinsLipidsSmall moleculesAtomsNucleusMost bacteriaMitochondrionLight microscopeElectron microscopeElectron microscopeFigure 6.2Human heightMeasurements1 centimeter (cm) = 102 meter (m) = 0.4 inch1 millimeter (mm) = 10–3 m1 micrometer (µm) = 10–3 mm = 10–6 m1 nanometer (nm) = 10–3 mm = 10–9 mCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings–Use different methods for enhancing visualization of cellular structuresTECHNIQUE RESULTBrightfield (unstained specimen). Passes light directly through specimen. Unless cell is naturally pigmented or artificially stained, image has little contrast. [Parts (a)–(d) show a human cheek epithelial cell.](a)Brightfield (stained specimen). Staining with various dyes enhances contrast, but most staining procedures require that cells be fixed (preserved).(b)Phase-contrast. Enhances contrast in unstained cells by amplifying variations in density within specimen; especially useful for examining living, unpigmented cells.(c)50 µmFigure 6.3Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsDifferential-interference-contrast (Nomarski). Like phase-contrast microscopy, it uses optical modifications to exaggerate differences indensity, making the image appear almost 3D.Fluorescence. Shows the locations of specific molecules in the cell by tagging the molecules with fluorescent dyes or antibodies. These fluorescent substances absorb ultraviolet radiation and emit visible light, as shown here in a cell from an artery.Confocal. Uses lasers and special optics for “optical sectioning” of fluorescently-stained specimens. Only a single plane of focus is illuminated; out-of-focus fluorescence above and below the plane is subtracted by a computer. A sharp image results, as seen in stained nervous tissue (top), where nerve cells are green, support cells are red, and regions of overlap are yellow. A standard fluorescence micrograph (bottom) of this relatively thick tissue is blurry.50 µm50 µm(d)(e)(f)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Electron microscopes (EMs)–Focus a beam of electrons through a specimen (TEM) or onto its surface (SEM)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•The scanning electron microscope (SEM)–Provides for detailed study of the surface of a specimenTECHNIQUERESULTSScanning electron micro-scopy (SEM). Micrographs takenwith a scanning electron micro-scope show a 3D image of the surface of a specimen. This SEM shows the surface of a cell from a rabbit trachea (windpipe) covered with motile organelles called cilia. Beating of the cilia helps moveinhaled debris upward toward the throat.(a)Cilia1 µmFigure 6.4 (a)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•The transmission electron microscope (TEM)–Provides for detailed study of the internal ultrastructure of cellsTransmission electron micro-scopy (TEM). A transmission electron microscope profiles a thin section of a specimen. Here we see a section through a tracheal cell, revealing its ultrastructure. In preparing the TEM, some cilia were cut along their lengths, creating longitudinal sections, while other cilia were cut straight across, creating cross sections.(b)Longitudinalsection ofciliumCross sectionof cilium1 µmFigure 6.4 (b)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsIsolating Organelles by Cell Fractionation•Cell fractionation–Takes cells apart and separates the major organelles from one anotherCopyright © 2005 Pearson Education,