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Chapter 7Chapter 7
Cell Structure & Cell Structure & FunctionFunction
Chapter 7 2 Are All Cells Alike?Are All Cells Alike?
All living things are made up of cells. Some All living things are made up of cells. Some organisms are composed of only one cell. organisms are composed of only one cell. Other organisms are made up of many Other organisms are made up of many cells.cells.
1. What are the advantages of a one-celled 1. What are the advantages of a one-celled organism?organism?
2. What are the advantages of an organism 2. What are the advantages of an organism that is made up of that is made up of
many cells?many cells?
Chapter 7 3
The History of Cell StudyThe History of Cell Study
Robert Hooke-1665Robert Hooke-1665• Coined the word “cell” Coined the word “cell” • Looked at cork cellsLooked at cork cells
Anton van Leuwenhoek 1674Anton van Leuwenhoek 1674• Viewed single celled organisms in drop of Viewed single celled organisms in drop of
water.water.Robert Brown -1831Robert Brown -1831
• Discovered the "nucleus"Discovered the "nucleus"
Chapter 7 4
Theodor Schwann - 1838Theodor Schwann - 1838• Cells are unit of biological structureCells are unit of biological structure
Mattias Schleiden – ca. 1850Mattias Schleiden – ca. 1850• Cells are the fundamental basis of Cells are the fundamental basis of
lifelifeVirchow -1858Virchow -1858
• All cells come from cellsAll cells come from cells
Chapter 7 5
Cell TheoryCell Theory
All living things are composed of one or All living things are composed of one or more cellsmore cells
Cells are:Cells are:
• Basic unit of structureBasic unit of structure
• Basic unit of functionBasic unit of function
All cells come from preexisting cellsAll cells come from preexisting cells
Chapter 7 6
MicroscopesMicroscopesHooke’s Hooke’s
drawings of drawings of corkcork
Early light Early light microscopemicroscope
Electron Electron microscopemicroscope
Chapter 7 7
Relative SizesRelative Sizes
100 m
10 m
1 m
10 cm
1 cm
1 mm
100 m
10 m
1 m
100 nm
10 nm
1 nm
0.1 nm
Elec
tron
Mic
rosc
ope
Ligh
t Mic
rosc
ope
Una
ided
eye
Spec
ial
E.M
.
Eukaryotic CellsEukaryotic Cells
MitochondrionMitochondrion
VirusVirus
ProteinsProteins
AtomsAtoms
Chapter 7 8
Attributes of CellsAttributes of Cells
Cell sizeCell size
• 1–100 µm1–100 µm
• Why is there a limit to cell size?Why is there a limit to cell size?
– Surface-to-volume (S/V) ratioSurface-to-volume (S/V) ratio
– Distance from surface to centerDistance from surface to center
Chapter 7 9
Microscopic ImagesMicroscopic Images
ParameciumParamecium
LightLightMicrographMicrograph Scanning ElectronScanning Electron
Micrograph Micrograph
Transmission ElectronTransmission Electron Micrograph Micrograph
Scanning ElectronScanning Electron Micrograph Micrograph
Chapter 7 10
Cell TypesCell Types
Prokaryotic:Prokaryotic:• Smaller, 1—5 µmSmaller, 1—5 µm• No organellesNo organelles• No nucleusNo nucleus• DNA in circular loop DNA in circular loop
Eukaryotic:Eukaryotic:• Larger, 8—100 µmLarger, 8—100 µm• Membranous organellesMembranous organelles• NucleusNucleus• DNA in linear chromosomesDNA in linear chromosomes
Chapter 7 11
Generalized ProkaryoteGeneralized Prokaryote
CapsuleCapsule
Cell WallCell WallPlasmaPlasmaMembraneMembrane
CytosolCytosol
Nucleoid DNANucleoid DNA
FlagellumFlagellum
Plasmid DNAPlasmid DNA
Chapter 7 12
Prokaryotic Cell
Cell membrane
Cell membrane
Cytoplasm
Cytoplasm
Nucleus
Organelles
Eukaryotic Cell
Go to Section:
Chapter 7 13
Eukaryotic Cell Structure 1Eukaryotic Cell Structure 1
All cells possess a plasma membrane, All cells possess a plasma membrane, cytoplasm, genetic materialcytoplasm, genetic material
Plasma membrane has phospholipid Plasma membrane has phospholipid bilayer, embedded glycoproteinsbilayer, embedded glycoproteins• Isolates cytoplasm from environmentIsolates cytoplasm from environment
• Regulates molecular movement into and out Regulates molecular movement into and out of cellof cell
• Interacts with other cells/environmentInteracts with other cells/environment
Chapter 7 14
Chapter 7 15
Chapter 7 16
Chapter 7 17
Eukaryotic Cell Structure 2Eukaryotic Cell Structure 2
Genetic material - DNA, found in the Genetic material - DNA, found in the nucleusnucleus
CytoplasmCytoplasm• Cytosol (the fluid part)Cytosol (the fluid part)
– WaterWater
– SaltsSalts
– Organic monomers and polymersOrganic monomers and polymers
• OrganellesOrganelles
Chapter 7 18
Generalized Cell Generalized Cell AnimalAnimal
CellCellAnimalAnimal
CellCell
PlantPlantCellCell
PlantPlantCellCell
NucleusNucleus
GolgiGolgi
MitochondriaMitochondria
EndoplasmicEndoplasmicReticulumReticulum
CentriolesCentrioles ChloroplastsChloroplasts
Chapter 7 19
AnimalAnimalCellCell
AnimalAnimalCellCell
PlantPlantCellCell
PlantPlantCellCell
Generalized CellGeneralized Cell
NucleolusNucleolus
RibosomesRibosomes
Central VacuoleCentral Vacuole
Smooth E.R.Smooth E.R. Cell WallCell Wall
Chapter 7 20
A. Cell Membrane
1. Regulates what enters and exits the cell
2. Provides protection and support
3. Made of double-layered sheet called- lipid bilayer
Lipid molecules
Chapter 7 21
NucleusNucleus
Cell control and geneticsCell control and genetics• Genes in thread-like chromosomes - chromatinGenes in thread-like chromosomes - chromatin• Control production of all proteinsControl production of all proteins
Bounded by nuclear envelopeBounded by nuclear envelope• Double lipid bilayerDouble lipid bilayer• Pores regulate transport Pores regulate transport
Not always at center of cellNot always at center of cell
Contains nucleolus of RNAContains nucleolus of RNA• Site of ribosome assemblySite of ribosome assembly
Chapter 7 22
The NucleusThe NucleusNucleolusNucleolus
PoresPores
Chromatin ThreadsChromatin Threads(Chromosomes)(Chromosomes) NuclearNuclear
EnvelopeEnvelope
Chapter 7 23
Nucleus:Nucleus:Freeze Etched ScanFreeze Etched Scan
PlasmaPlasmaMembraneMembrane
NucleusNucleus
NuclearNuclearPoresPores
Chapter 7 24
ChromosomesChromosomes
NucleoliNucleoli
NucleusNucleus
Cell WallCell Wall
ChromosomesChromosomes
Chapter 7 25
RibosomesRibosomes
Chapter 7 26
Endoplasmic ReticulumEndoplasmic Reticulum
Folded membranes attached to nucleusFolded membranes attached to nucleus
• Rough ER - protein synthesisRough ER - protein synthesis
– Ribosomes chain amino acids into polypeptideRibosomes chain amino acids into polypeptide
– Ribosomes on outside surface of rough ERRibosomes on outside surface of rough ER
– Composed of rRNA and proteinsComposed of rRNA and proteins
• Smooth ERSmooth ER
– Lipid synthesisLipid synthesis
Chapter 7 27
Endoplasmic ReticulumEndoplasmic Reticulum
RibosomesRibosomes
UnitUnitMembraneMembrane
VesiclesVesiclesformingforming
Chapter 7 28
Rough vs. Smooth ER: TEMRough vs. Smooth ER: TEM
Rough ERRough ERRough ERRough ER
Smooth ERSmooth ERSmooth ERSmooth ER
RibosomesRibosomes
Chapter 7 29
Golgi ApparatusGolgi Apparatus
Processes material synthesized by ERProcesses material synthesized by ER
Packages material and provides “address Packages material and provides “address label”label”
Distributes material in sacs called vesiclesDistributes material in sacs called vesicles
Some for inside, others outside cellSome for inside, others outside cell
Secretory vesicles merge with cell Secretory vesicles merge with cell membranemembrane
Synthesis and transport of polysaccharidesSynthesis and transport of polysaccharides
Chapter 7 30
The Golgi ComplexThe Golgi ComplexMaterial Material
ReceivedReceivedFrom ERFrom ER
Material DestinedMaterial Destinedfor Exportfor Export
TEMTEM
Chapter 7 31
LysosomesLysosomes
Produced by Golgi apparatusProduced by Golgi apparatus
Vesicles containing hydrolytic enzymesVesicles containing hydrolytic enzymes
Digestive system of cellDigestive system of cell
Digest material engulfed by cellDigest material engulfed by cell
Digest and recycle damaged organellesDigest and recycle damaged organelles
Chapter 7 32
The Flow of MembraneThe Flow of Membrane
LysosomeLysosome
Destined forDestined forExportExport
GolgiGolgiEndoplasmicEndoplasmic
ReticulumReticulum
Destined forDestined forGolgiGolgi
Chapter 7 33
Contractile VacuoleContractile Vacuole
Special kidney-like organelleSpecial kidney-like organelle
Draws water in from cytoplasm & expels itDraws water in from cytoplasm & expels it
Important for some single-celled freshwater Important for some single-celled freshwater animalsanimals
Requires ATPRequires ATP
Chapter 7 34
Contractile VacuolesContractile Vacuoles
1111
2222
Paramecium sp.
Expelling WaterExpelling Waterto Outsideto Outside
ExpandedExpandedwith Waterwith Water
Chapter 7 35
Central VacuolesCentral Vacuoles
Large, water-filled spaces (cell sap)Large, water-filled spaces (cell sap)
Can take up over 90% of cell volumeCan take up over 90% of cell volume
Surrounded by tonoplast (single membrane)Surrounded by tonoplast (single membrane)
Functions:Functions:• Storage of pigments (red/blue), acids, salts, Storage of pigments (red/blue), acids, salts,
wasteswastes
• Maintain cell pressure (turgor pressure)Maintain cell pressure (turgor pressure)
Chapter 7 36
Plant Wilting &Plant Wilting &the Central Vacuolethe Central Vacuole
VacuoleVacuole(tonoplast)(tonoplast) Cell WallCell Wall
Cyt
opla
sm
Cyt
opla
sm
NormalNormalPlant CellPlant Cell
In SaltIn SaltWaterWater
Space between Cell WallSpace between Cell Walland Cell Membraneand Cell Membrane
Normal
In Salt Water
Chapter 7 37
MitochondriaMitochondria
““Powerhouse” of cellPowerhouse” of cell
NumerousNumerous
Glucose catabolismGlucose catabolism
Bounded by double membraneBounded by double membrane
Matrix / cristaeMatrix / cristae
Have their own DNA and ribosomes; self-Have their own DNA and ribosomes; self-replicatingreplicating
Chapter 7 38
The MitochondrionThe Mitochondrion
CristaeCristaeMatrixMatrix
OuterOuterMembraneMembrane
InnerInnerMembraneMembrane
Chapter 7 39
ChloroplastChloroplast
Green plants onlyGreen plants only
Captures light energyCaptures light energy
Produces carbohydrate from COProduces carbohydrate from CO22 and H and H22OO
In cytoplasm of mostly mesophyll cells of In cytoplasm of mostly mesophyll cells of leafleaf
Stroma / grana (thylakoid stacks)Stroma / grana (thylakoid stacks)
Have their own DNA and ribosomes; self-Have their own DNA and ribosomes; self-replicatingreplicating
Chapter 7 40
The ChloroplastThe Chloroplast
ThylakoidsThylakoids
OuterOuterMembraneMembrane
InnerInnerMembraneMembrane
One GranumOne Granum
StromaStroma
Chapter 7 41
PlastidsPlastids
Associated w/photosynthesisAssociated w/photosynthesis
Double bilipid membraneDouble bilipid membrane
Many functionsMany functions
• ChloroplastsChloroplasts
• Storage of pigmentsStorage of pigments
• Storage of photosynthetic productsStorage of photosynthetic products
Chapter 7 42
PlastidsPlastids
DoubleDoubleBilipidBilipid
MembraneMembrane
StarchStarchGranulesGranules
Chapter 7 43
CytoskeletonCytoskeleton
Protein fibersProtein fibers• Cell shape; networks of intermediate Cell shape; networks of intermediate
filamentsfilaments• Cell movement; microfilaments & Cell movement; microfilaments &
microtubulesmicrotubules– Amoeboid movementAmoeboid movement– Muscle contractionMuscle contraction– Cell migration during developmentCell migration during development
• Organelle movement & suspensionOrganelle movement & suspension– Cyclosis; pathways for vesicle migrationCyclosis; pathways for vesicle migration
• Cell divisionCell division
Chapter 7 44
The CytoskeletonThe Cytoskeleton
MicrotubuleMicrotubule
MicrofilamentsMicrofilaments
IntermediateIntermediateFilamentsFilaments
Actin subunitsActin subunits
Tubulin subunitsTubulin subunits
EndoplasmicReticulum
Mitochondrion
PlasmaMembrane
Chapter 7 45
Cilia and FlagellaCilia and Flagella
Tubular extensions of plasma membraneTubular extensions of plasma membrane
Movement of fluid, or locomotionMovement of fluid, or locomotion
Two functionally different typesTwo functionally different types• Cilia: numerous, paddle-like, synchronizedCilia: numerous, paddle-like, synchronized• Flagella: longer, fewer, more whip-likeFlagella: longer, fewer, more whip-like
Filled with microtubulesFilled with microtubules• 9 pairs in periphery; 2 singlets in center9 pairs in periphery; 2 singlets in center• ““9+2” arrangement9+2” arrangement
Chapter 7 46
Cilia & FlagellaCilia & Flagella““Sheath” Sheath” X.S.X.S.
CellCellMembraneMembrane
ShaftShaft
BaseBase(a Centriole)(a Centriole)
T.E.M.
T.E.M.
Paramecium
X.S.X.S.
11112222
3333
4444
5555
Chapter 7 47
Flagellum PartsFlagellum PartsShaft, l.s.Shaft, l.s.
Shaft,Shaft,x.s.x.s. Microtubule Microtubule DoubletsDoublets
Cell MembraneCell Membrane
Dynein ArmsDynein Arms
Central Central SingletsSinglets
Microtubule Microtubule TripletsTriplets
Basal BodyBasal BodyBasal Body,Basal Body,
x.s.x.s.
Chapter 7 48
Movement of FlagellaMovement of Flagella
Scanning E.M.Scanning E.M.of sperm on eggof sperm on eggScanning E.M.Scanning E.M.
of sperm on eggof sperm on egg
Corkscrew Movement(Pulls)
Whipping Movement(Pushes)
Water Water
Chapter 7 49
Movement of CiliaMovement of CiliaPower Stroke Recovery Stroke
Water
Scanning E.M.Scanning E.M.of a ciliateof a ciliate
Chapter 7Chapter 7
Chapter 7 51
Chapter 7 52
Chapter 7 53
Chapter 7 54
Chapter 7 55
Chapter 7 56
Chapter 7 57
Chapter 7 58
Chapter 7Chapter 7
The endThe endThe endThe end
