Chapter 6You must check this website:Overview: The Importance of CellsConcept 6.1: To study cells, biologists use microscopes and the tools of biochemistryMicroscopyLE 6-2Slide 7LE 6-3aLE 6-3bSlide 10LE 6-4Slide 12Isolating Organelles by Cell FractionationLE 6-5aLE 6-5bThere is correlation between the structure of cells and their functionHistoryConcept 6.2: Eukaryotic cells have internal membranes that compartmentalize their functionsComparing Prokaryotic and Eukaryotic CellsSlide 20LE 6-6Slide 22LE 6-7Slide 24Slide 25LE 6-8A Panoramic View of the Eukaryotic CellLE 6-9aLE 6-9bConcept 6.3: The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomesThe Nucleus: Genetic Library of the CellLE 6-10Ribosomes: Protein Factories in the CellLE 6-11Concept 6.4: The endomembrane system regulates protein traffic and performs metabolic functions in the cellThe Endoplasmic Reticulum: Biosynthetic FactoryLE 6-12Functions of Smooth ERFunctions of Rough ERThe Golgi Apparatus: Shipping and Receiving CenterLE 6-13Lysosomes: Digestive CompartmentsLE 6-14aLE 6-14bVacuoles: Diverse Maintenance CompartmentsSlide 46LE 6-15The Endomembrane System: A ReviewLE 6-16-1LE 6-16-2LE 6-16-3Concept 6.5: Mitochondria and chloroplasts change energy from one form to anotherMitochondria: Chemical Energy ConversionLE 6-17Chloroplasts: Capture of Light EnergyLE 6-18Peroxisomes: OxidationLE 6-19Concept 6.6: The cytoskeleton is a network of fibers that organizes structures and activities in the cellLE 6-20Roles of the Cytoskeleton: Support, Motility, and RegulationLE 6-21aLE 6-21bComponents of the CytoskeletonSlide 65Slide 66Slide 67MicrotubulesCentrosomes and CentriolesLE 6-22Cilia and FlagellaLE 6-23aLE 6-23bSlide 74LE 6-24Slide 76LE 6-25aLE 6-25bMicrofilaments (Actin Filaments)LE 6-26Slide 81LE 6-27aSlide 83LE 6-27bSlide 85LE 6-27cIntermediate FilamentsConcept 6.7: Extracellular components and connections between cells help coordinate cellular activitiesCell Walls of PlantsSlide 90LE 6-28The Extracellular Matrix (ECM) of Animal CellsLE 6-29aLE 6-29bIntercellular JunctionsPlants: PlasmodesmataLE 6-30Animals: Tight Junctions, Desmosomes, and Gap JunctionsLE 6-31The Cell: A Living Unit Greater Than the Sum of Its PartsLE 6-32Copyright © 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 CummingsYou must check this website:•www.cellsalive.comCopyright © 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 live•Cell structure is correlated to function•All cells are related by their descent from earlier cellsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsConcept 6.1: To study cells, biologists use microscopes and the tools of biochemistry•Though usually too small to be seen by the unaided eye, cells can be complexCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsMicroscopy•Scientists use microscopes to visualize cells too small to see with the naked eye•In a light microscope (LM), visible light passes through a specimen and then through glass lenses, which magnify the image•The minimum resolution of an LM is about 200 nanometers (nm), the size of a small bacteriumLE 6-2LE 6-2Measurements1 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 µm = 10–9 m10 m1 mHuman heightLength of somenerve andmuscle cellsChicken egg0.1 m1 cmFrog egg1 mm100 µmMost plant andanimal cells10 µmNucleus1 µmMost bacteriaMitochondrionSmallest bacteriaViruses100 nm10 nmRibosomesProteinsLipids1 nmSmall moleculesAtoms0.1 nmUnaided eyeLight microscopeElectron microscopeCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•LMs can magnify effectively to about 1,000 times the size of the actual specimen•Various techniques enhance contrast and enable cell components to be stained or labeled•Most subcellular structures, or organelles, are too small to be resolved by a LMLE 6-3aLE 6-3aBrightfield (unstained specimen)50 µmBrightfield (stained specimen)Phase-contrastLE 6-3bLE 6-3b50 µm50 µmConfocalDifferential-interference-contrast (Nomarski)FluorescenceCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings•Two basic types of electron microscopes (EMs) are used to study subcellular structures •Scanning electron microscopes (SEMs) focus a beam of electrons onto the surface of a specimen, providing images that look 3D. Its magnification is usually about 1000 times greater than light microscopes.•Transmission electron microscopes (TEMs) focus a beam of electrons through a specimen •TEMs are used mainly to study the internal ultrastructure of cellsLE 6-4LE 6-41 µm1 µmScanning electronmicroscopy (SEM)CiliaLongitudinalsection ofciliumTransmission electronmicroscopy (TEM)Cross sectionof ciliumCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings–The electron microscope•Allows greater magnification and reveals cellular details SEM 2,000 TEM 2,800 Figure 4.1CFigure 4.1DCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsIsolating Organelles by Cell Fractionation•Cell fractionation takes cells apart and separates the major organelles from one another•Ultracentrifuges fractionate cells into their component parts•Cell fractionation enables scientists to determine the functions of organellesLE 6-5aLE 6-5aHomogenizationHomogenateTissuecellsDifferential centrifugationLE 6-5bLE 6-5bPellet rich innuclei andcellular debrisPellet rich inmitochondria (and chloro-plasts if cellsare from a plant)Pellet rich in“microsomes”(pieces of plasmamembranes andcells’ internalmembranes)Pellet rich inribosomes150,000 g3 hr80,000 g60 min20,000 g20 min1000 g(1000 times theforce of gravity)10 minSupernatant pouredinto next tubeCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsThere is correlation between the structure of cells and their functionEx: The shapes of muscles cells, sperm cells, red blood cells,, nerve cells are appropriate for their function. Example: the flat tile like epithelial cells of the skin fit