Chapter 4-Chapter 4-A View of the CellA View of the Cell
4.1-The Discovery of Cells4.1-The Discovery of Cells
Cells are the basic units of living Cells are the basic units of living organismsorganisms
Development of the microscope allowed Development of the microscope allowed scientists to view cellsscientists to view cells
Cell TheoryCell Theory 1665-Robert Hooke1665-Robert Hooke
Uses compound microscope to observe Uses compound microscope to observe corkcork
Hollow boxes…..CELLS!!Hollow boxes…..CELLS!!
1830s-Schleiden and Schwann1830s-Schleiden and Schwann Schleiden-all plants are composed of Schleiden-all plants are composed of
cells!cells! Schwann-all animals are composed of Schwann-all animals are composed of
cells!cells!
Three Parts of Cell TheoryThree Parts of Cell Theory
1. All organisms composed of one or more 1. All organisms composed of one or more cells.cells.
2. Cell is the basic unit of organization of 2. Cell is the basic unit of organization of organisms.organisms.
3. All cells come from preexisting cells.3. All cells come from preexisting cells.
History of the MicroscopeHistory of the Microscope 1665-Hooke’s Microscope1665-Hooke’s Microscope
Three lensesThree lenses Poor QualityPoor Quality Little detailLittle detail
1700-Anton van Leeuwenhoek1700-Anton van Leeuwenhoek Built over 240 microscopes!Built over 240 microscopes! Single LensSingle Lens Better QualityBetter Quality Observed red blood cells & bacteriaObserved red blood cells & bacteria
Mid 1800s-Compound Light MicroscopeMid 1800s-Compound Light Microscope Series of lensesSeries of lenses Light passes through object then lensLight passes through object then lens More detailMore detail
1940s-Electron Microscopes1940s-Electron Microscopes Beam of electrons through magnetic fieldBeam of electrons through magnetic field Specimen in vacuumSpecimen in vacuum Only view dead cells or organismsOnly view dead cells or organisms
1.SEM-Scanning Electron Microscope1.SEM-Scanning Electron Microscope Surface of specimen-3D Picture!Surface of specimen-3D Picture!
2.TEM-Transmission Electron Microscope2.TEM-Transmission Electron Microscope Through the specimenThrough the specimen Magnify 100s or 1,000s of times!Magnify 100s or 1,000s of times!
3.STM-Scanning Tunneling Microscope3.STM-Scanning Tunneling Microscope Arrangement of atoms on surfaceArrangement of atoms on surface Map hills and valleysMap hills and valleys
Basic Cell Types…Basic Cell Types…
Look at internal organization!Look at internal organization!
Prokaryotes-lacks internal structuresProkaryotes-lacks internal structures
Eukaryotes-membrane bound, Eukaryotes-membrane bound, internal structures.internal structures. Structures called organellesStructures called organelles Largest organelle = NUCLEUS!Largest organelle = NUCLEUS!
Section 4.2-Eukaryotic Cell Section 4.2-Eukaryotic Cell StructureStructure
Must have boundaries!Must have boundaries!
Plasma MembranePlasma Membrane Boundary between cell & environmentBoundary between cell & environment FlexibilityFlexibility Controls movement of materialsControls movement of materials
Cell Wall-only plant cells!Cell Wall-only plant cells! Rigid, surrounds membraneRigid, surrounds membrane Thicker, stronger network for structural Thicker, stronger network for structural
supportsupport
Fluid-Mosaic MembraneFluid-Mosaic Membrane
GET UNDER CONTROL!!!!GET UNDER CONTROL!!!!
Nucleus-contains cell’s DNA, manages Nucleus-contains cell’s DNA, manages cell functioncell function
Surrounded by nuclear envelopeSurrounded by nuclear envelope Double membrane-pores allow movementDouble membrane-pores allow movement
Chromatin-long strands of DNAChromatin-long strands of DNA Packed into chromosomesPacked into chromosomes
NucleusNucleus
NucleolusNucleolus Region inside nucleusRegion inside nucleus Produces particles for protein synthesisProduces particles for protein synthesis
Particles are called ribosomesParticles are called ribosomes Cell assembles enzymes according to Cell assembles enzymes according to
DNADNA Not bound by membraneNot bound by membrane
NucleolusNucleolus
Assembly, Transport, & Assembly, Transport, & StorageStorage
Cytoplasm-outside nucleus, surrounds Cytoplasm-outside nucleus, surrounds organellesorganelles Clear liquidClear liquid Important chemical reactions (protein Important chemical reactions (protein
assembly) take place hereassembly) take place here
Endoplasmic Reticulum (ER)-Endoplasmic Reticulum (ER)- Network of interconnected compartmentsNetwork of interconnected compartments Surface folded into cellSurface folded into cell
Tissues in a box!Tissues in a box! Site for lipid synthesis in cellSite for lipid synthesis in cell
Smooth or Rough?Smooth or Rough?
Smooth ERSmooth ER Lacks ribosomes on surfaceLacks ribosomes on surface
Rough ERRough ER Studded with ribosomes on surfaceStudded with ribosomes on surface
ER acts as cell’s delivery system!ER acts as cell’s delivery system!
Structures for StorageStructures for Storage Golgi ApparatusGolgi Apparatus
Closely stacked, flattened membrane sacsClosely stacked, flattened membrane sacs Receives proteins and lipidsReceives proteins and lipids Modifies them chemically, repackagesModifies them chemically, repackages Distributes them throughout membraneDistributes them throughout membrane
Vacuole-sac of fluidVacuole-sac of fluid Temporary storage of food, enzymes etc.Temporary storage of food, enzymes etc. Animal cell-small and numerousAnimal cell-small and numerous Plant cell-single large vacuole for waterPlant cell-single large vacuole for water
Reduce, Reuse, RECYCLE!Reduce, Reuse, RECYCLE!
LysosomesLysosomes Digest excess or worn out cell parts, Digest excess or worn out cell parts,
food particles, and invading food particles, and invading viruses/bacteriaviruses/bacteria
Membrane protects digestive enzymes Membrane protects digestive enzymes from rest of cellfrom rest of cell
Energy TransformersEnergy Transformers MitochondriaMitochondria
Break down food-convert to energy!Break down food-convert to energy! Peanut-shapedPeanut-shaped Highly folded inner membrane for more Highly folded inner membrane for more
energy storageenergy storage
Chloroplasts-plants only!Chloroplasts-plants only! Transform light energy into chemical energyTransform light energy into chemical energy Chlorophyll-traps energy from sunChlorophyll-traps energy from sun
Green color!Green color!
NRG!!NRG!!
Support and LocomotionSupport and Locomotion CytoplasmCytoplasm
1. Cytoskeleton-network of fibrous elements1. Cytoskeleton-network of fibrous elementsAct as scaffold for organelle supportAct as scaffold for organelle support
2. Microtubules-thin, hollow cylinders2. Microtubules-thin, hollow cylindersMade of proteinMade of protein
3. Microfilaments-thin, solid fibers3. Microfilaments-thin, solid fibersBoth make up most of cytoskeletonBoth make up most of cytoskeleton
LET’S GET MOVING!LET’S GET MOVING!
CiliaCilia Short, numerous hair-like projectionsShort, numerous hair-like projections On cell’s surfaceOn cell’s surface Movement like “the wave!”Movement like “the wave!”
FlagellaFlagella Longer projectionsLonger projections Whip-like motionWhip-like motion One or two per cellOne or two per cell
Flagella vs CiliaFlagella vs Cilia
Cellular OrganizationCellular Organization 1. Single-celled organisms: 1. Single-celled organisms:
UnicellularUnicellular 2. Many-celled organisms: 2. Many-celled organisms:
MulticellularMulticellular 3. Cells functioning together for 3. Cells functioning together for
activity: Tissuesactivity: Tissues 4. Two or more tissues functioning 4. Two or more tissues functioning
together: Organstogether: Organs 5. Organs working together to carry 5. Organs working together to carry
out major life functions:Organ Systemout major life functions:Organ System