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Cells

CellsLevels of OrganizationCells produce tissuesTissues produce organsOrgans produce organ systemsOrgans systems produce organisms

Levels of Organization3Introduction The basic organizational structure of the human body is the cell.

There are 50-100 trillion cells in the human body.

Differentiation is when cells specialize.

As a result of differentiation, cells vary in size and shape due to their unique function.

http://www.natgeoeducationvideo.com/film/1080/the-human-cell

43.2: A Composite Cell Also called a typical cell Major parts include: Nucleuscontains DNA Cytoplasmcellular contents between plasma membrane &nucleus Plasma membraneselective barrier

MicrotubulesFlagellumNuclear envelopeBasal bodyChromatinRibosomesCell membraneMitochondrionCiliaMicrotubulesMicrotubuleCentriolesMicrovilliLysosomesNucleolusNucleusPhospholipid bilayerSmoothEndoplasmicreticulumRoughEndoplasmicreticulumCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.GolgiapparatusSecretoryvesicleshttp://www.wisc-online.com/objects/ViewObject.aspx?ID=AP11403

5Cell Membrane(aka Plasma Membrane) Outer limit of the cell Controls what moves in and out of the cell Selectively permeable Phospholipid bilayer Water-soluble heads form surfaces (hydrophilic) Water-insoluble tails form interior (hydrophobic) Permeable to lipid-soluble substances

Cholesterol stabilizes the membrane Proteins: Receptors Pores, channels and carriers Enzymes Self-markers6Cell Membrane

Cell membraneCell membrane(b)(a) Heads ofphospholipidTails ofphospholipidCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.a: Biophoto Associates/Photo Researchers, Inc.Fibrous proteinCarbohydrateGlycolipidGlycoproteinExtracellular sideof membraneCytoplasmic sideof membraneCholesterolmoleculesGlobularproteinDoublelayer ofPhospholipidmoleculesHydrophobicfatty acidtailHydrophilicPhosphateheadCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Cell MembraneElectrochemical Gradient

due to selective permeability

difference in concentration of chemicals across membrane

difference in distribution of charges across the membrane

difference is the membrane potentialCell MembraneElectrochemical GradientCell MembraneBoundary of the cellMade of a phospholipid bilayer

Cell Membrane8Emphasize word parts here:phospho= phosphate head; lipid= fatty acid tailbi= 2Cell OrganellesOrganelle= little organAll the stuff in between the organelles is cytosolEverything in a cell except the nucleus is cytoplasm

Cell Organelles9You may or may not wish to distinguish between cytosol and cytoplasm. The correct use of each term is shown here. Most high school textbooks, however, use the word cytoplasm to mean cytosol.10Cytoplasm Cytosol = water

Organelles = solidsCytoplasm is really like a Jello fruit salad where the Jello is the cytosol and the fruits (oranges, grapes, bananas, maybe walnuts, etc.) are the organelles.Cytoplasm11OrganellesEndoplasmic Reticulum (ER) Connected, membrane-bound sacs, canals, and vesicles Transport system Rough ER Studded with ribosomes Smooth ER Lipid synthesis Added to proteinsarriving from rough ER Break down of drugsRibosomes Free floating or connected to ER Provide structural support and enzyme activityto amino acids to form protein (protein synthesis)

MembranesRibosomesMembranes(b)(c)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.OrganellesEndoplasmic ReticulumA.k.a. ERConnected to nuclear membraneHighway of the cellRough ER: studded with ribosomes; it makes proteinsSmooth ER: no ribosomes; it makes lipids

Endoplasmic Reticulum (ER)12Its not necessary that the students can read the labels here; just point out the black dots are ribosomes.RibosomeSite of protein synthesisFound attached to rough ER or floating free in cytosolProduced in a part of the nucleus called the nucleolus

Remember where ribosomes are found in the cell and why?Ribosomes13A polypeptide is a chain of amino acids. In this diagram, you can see the ribosome is making a polypeptide, also known as a protein.14OrganellesGolgi apparatus Stack of flattened, membranous sacs Modifies, packagesand delivers proteinsVesicles Membranous sacs Store substances

Inner membraneOuter membraneCristae(a)(b)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.a: Bill Longcore/Photo Researchers, Inc.Mitochondria Membranous sacs with inner partitions Generate energyGolgi ApparatusGolgi ApparatusLooks like a stack of platesStores, modifies and packages proteinsMolecules transported to and from the Golgi by means of vesicles

Golgi Apparatus15AKA Golgi Complex. It is not necessary that the students read the labels, this diagram gives them a general idea of the Golgis shape.16OrganellesLysosomes Enzyme-containing sacs Digest worn out cell parts or unwanted substancesPeroxisomes Enzyme-containing sacs Break down organic moleculesCentrosome Two rod-like centrioles Used to produce cilia and flagella Distributes chromosomes during cell division

(a)(b)Centriole(cross-section)Centriole(longitudinal section)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.a: Don W. Fawcett/Visuals UnlimitedOrganelles

LysosomesGarbage disposal of the cellContain digestive enzymes that break down wastes

Which organelles do lysosomes work with?Lysosomeshttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__lysosomes.html

17Students should recognize the shapes of the Golgi and ER even if they cannot read the captions.MitochondriaPowerhouse of the cellCellular respiration occurs here to release energy for the cell to useBound by a double membraneHas its own strand of DNA

Mitochondria18Explain that this diagram shows the mitochondria cut open to reveal the internal membranes.19OrganellesCilia Short hair-like projections Propel substances on cell surfaceFlagellum Long tail-like projection Provides motility to sperm

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.a: Oliver Meckes/Photo Researchers, Inc. Colin Anderson/Brand X/CORBISOrganelles

20Cell Nucleus Is the control center of the cell Nuclear membrane (envelope) Porous double membrane Separates nucleoplasm from cytoplasm Nucleolus Dense collection of RNA and proteins Site of ribosome production Chromatin Fibers of DNA and proteins Stores information for synthesis of proteinsCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.NucleusNucleolusChromatin(a)NuclearporesNuclearenvelopeCell Nucleus213.3: Movements Into and Out of the CellPassive (Physical) Processes Require no cellular energy and include: Simple diffusion Facilitated diffusion Osmosis FiltrationActive (Physiological) Processes Require cellular energy and include: Active transport Endocytosis Exocytosis Transcytosishttp://www.northland.cc.mn.us/biology/Biology1111/animations/transport1.html

22Simple Diffusion Movement of substances from regions of higher concentration to regions of lower concentration Oxygen, carbon dioxide and lipid-soluble substances

TimeSolute moleculeWater moleculeABAB(2)(3)PermeablemembraneAB(1)Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Simple Diffusion23Animation:How Diffusion WorksPlease note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

24Facilitated Diffusion Diffusion across a membrane with the help of a channel or carrier molecule Glucose and amino acids

Region of higherconcentrationTransportedsubstanceRegion of lowerconcentrationProtein carriermoleculeCellmembraneCopyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Facilitated Diffusion25Animation:How Facilitated Diffusion WorksPlease note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html

26Osmosis and Osmotic Pressure Osmotic Pressure ability of osmosis to generateenough pressure to move a volume of water Osmotic pressure increases as the concentrationof nonpermeable solutes increases Isotonic same osmotic pressure Hypertonic higher osmotic pressure (water loss) Hypotonic lower osmotic pressure (water gain)

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. David M. Phillips/Visuals Unlimited(b)(a)(c)Osmosis and Osmotic Pressurehttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

27Filtration Smaller molecules are forced through porous membranes Hydrostatic pressure important in the body Molecules leaving blood capillaries

Copyright The McGraw-Hill Companies