Chapter 5Chapter 5

Cell Structure & Cell Structure & FunctionFunction

Chapter 5 2

Wrong Chapter Wrong Chapter

Yeah, I know…I have the chapter numbers Yeah, I know…I have the chapter numbers for this chapter and the next one for this chapter and the next one confused…but I’ma Power Point Idiot and confused…but I’ma Power Point Idiot and can’t change them.can’t change them.

It gets worse towards the end of the book!It gets worse towards the end of the book!

Chapter 5 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

Robert Brown -1831Robert Brown -1831• Discovered the "nucleus"Discovered the "nucleus"

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 lifeCells are the fundamental basis of life

Virchow -1858Virchow -1858• All cells come from cellsAll cells come from cells

Chapter 5 4

The Cell TheoryThe Cell Theory

1.1. Every living organism is made up of at Every living organism is made up of at least one cell.least one cell.

2.2. Cells are the basic structural and Cells are the basic structural and functional units of mulicultural functional units of mulicultural organisms.organisms.

3.3. All cells arise from preexisting cells.All cells arise from preexisting cells.

Chapter 5 5

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 5 6

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 5 7

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 5 8

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 5 9

Generalized Cell Generalized Cell AnimalAnimal

CellCellAnimalAnimal

CellCell

PlantPlantCellCell

PlantPlantCellCell

NucleusNucleus

GolgiGolgi

MitochondriaMitochondria

EndoplasmicEndoplasmicReticulumReticulum

CentriolesCentrioles ChloroplastsChloroplasts

Chapter 5 10

AnimalAnimalCellCell

AnimalAnimalCellCell

PlantPlantCellCell

PlantPlantCellCell

Generalized CellGeneralized Cell

NucleolusNucleolus

RibosomesRibosomes

Central VacuoleCentral Vacuole

Smooth E.R.Smooth E.R. Cell WallCell Wall

Chapter 5 11

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 5 12

The CytoskeletonThe Cytoskeleton

MicrotubuleMicrotubule

MicrofilamentsMicrofilaments

IntermediateIntermediateFilamentsFilaments

Actin subunitsActin subunits

Tubulin subunitsTubulin subunits

EndoplasmicReticulum

Mitochondrion

PlasmaMembrane

Chapter 5 13

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” arrangement (for eukaryotes)9+2” arrangement (for eukaryotes)

Chapter 5 14

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 5 15

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 5 16

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 5 17

Movement of CiliaMovement of CiliaPower Stroke Recovery Stroke

Water

Scanning E.M.Scanning E.M.of a ciliateof a ciliate

Chapter 5 18

NucleusNucleus

Cell control and geneticsCell control and genetics• Genes in thread-like chromosomesGenes in thread-like chromosomes• 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

Chapter 5 19

The NucleusThe NucleusNucleolusNucleolus

PoresPores

Chromatin ThreadsChromatin Threads(Chromosomes)(Chromosomes) NuclearNuclear

EnvelopeEnvelope

Chapter 5 20

Nucleus functional partsNucleus functional parts

Chromatin – DNA not coiled up into a Chromatin – DNA not coiled up into a chromosomechromosome

Chromosome – DNA coils around proteins Chromosome – DNA coils around proteins called histones to create linear called histones to create linear chromosomeschromosomes

Contains nucleolus of RNAContains nucleolus of RNA• Site of ribosome assemblySite of ribosome assembly

Chapter 5 21

Nucleus:Nucleus:Freeze Etched ScanFreeze Etched Scan

PlasmaPlasmaMembraneMembrane

NucleusNucleus

NuclearNuclearPoresPores

Chapter 5 22

ChromosomesChromosomes

NucleoliNucleoli

NucleusNucleus

Cell WallCell Wall

ChromosomesChromosomes

Chapter 5 23

RibosomesRibosomes

-made of RNA and protein-made of RNA and protein

- Site of protein synthesisSite of protein synthesis

- Dark granules, (usually drawn as small Dark granules, (usually drawn as small circles)circles)

Chapter 5 24

RibosomesRibosomes

Chapter 5 25

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 5 26

Endoplasmic ReticulumEndoplasmic Reticulum

RibosomesRibosomes

UnitUnitMembraneMembrane

VesiclesVesiclesformingforming

Chapter 5 27

Rough vs. Smooth ER: TEMRough vs. Smooth ER: TEM

Rough ERRough ERRough ERRough ER

Smooth ERSmooth ERSmooth ERSmooth ER

RibosomesRibosomes

Chapter 5 28

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 5 29

The Golgi ComplexThe Golgi ComplexMaterial Material

ReceivedReceivedFrom ERFrom ER

Material DestinedMaterial Destinedfor Exportfor Export

TEMTEM

Chapter 5 30

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 5 31

The Flow of MembraneThe Flow of Membrane

LysosomeLysosome

Destined forDestined forExportExport

GolgiGolgiEndoplasmicEndoplasmic

ReticulumReticulum

Destined forDestined forGolgiGolgi

Chapter 5 32

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 5 33

Contractile VacuolesContractile Vacuoles

1111

2222

Paramecium sp.

Expelling WaterExpelling Waterto Outsideto Outside

ExpandedExpandedwith Waterwith Water

Chapter 5 34

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 5 35

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 5 36

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 5 37

The MitochondrionThe Mitochondrion

CristaeCristaeMatrixMatrix

OuterOuterMembraneMembrane

InnerInnerMembraneMembrane

Chapter 5 38

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 5 39

The ChloroplastThe Chloroplast

ThylakoidsThylakoids

OuterOuterMembraneMembrane

InnerInnerMembraneMembrane

One GranumOne Granum

StromaStroma

Chapter 5 40

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 5 41

PlastidsPlastids

DoubleDoubleBilipidBilipid

MembraneMembrane

StarchStarchGranulesGranules

Chapter 5 42

Generalized ProkaryoteGeneralized Prokaryote

CapsuleCapsule

Cell WallCell WallPlasmaPlasmaMembraneMembrane

CytosolCytosol

Nucleoid DNANucleoid DNA

FlagellumFlagellum

Plasmid DNAPlasmid DNA

Chapter 5 43

Prokaryote featuresProkaryote featuresSmall (<5 mircometers)Small (<5 mircometers)

Cytosol, DNA, ribosomes, cell membrane, Cytosol, DNA, ribosomes, cell membrane, (usually a cell wall too)(usually a cell wall too)

Nucleoid – location of chromosomeNucleoid – location of chromosome

Single, circular chromosomeSingle, circular chromosome

Plasmid – small DNA ring, separate from Plasmid – small DNA ring, separate from nucleoidnucleoid

Chapter 5 44

Prokaryotes (cont’d)Prokaryotes (cont’d)

Flagella with a 9+0 structure (never cillia)Flagella with a 9+0 structure (never cillia)

Capsule/slime layer – polysaccharide Capsule/slime layer – polysaccharide coatings for protectioncoatings for protection

Pili – protein jutting out from cell wallPili – protein jutting out from cell wall

Chapter 5Chapter 5

The endThe endThe endThe end