Cell Structure & Cell Structure & FunctionFunction
Robert Hooke-1665 Coined the word “cell” Looked at cork cells
Robert Brown -1831 Discovered the "nucleus"
Theodor Schwann - 1838 Cells are unit of biological structure
Mattias Schleiden – ca. 1850 Cells are the fundamental basis of life
Virchow -1858 All cells come from cells
1. Every living organism is made up of at least one cell.
2. Cells are the basic structural and functional units of mulicultural organisms.
3. All cells arise from preexisting cells.
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
Prokaryotic: Smaller, 1—5 µm No organelles No nucleus DNA in circular loop
Eukaryotic: Larger, 8—100 µm Membranous organelles Nucleus DNA in linear chromosomes
5
All cells possess a plasma membrane, cytoplasm, genetic material
Plasma membrane has phospholipid bilayer, embedded glycoproteins
Isolates cytoplasm from environment Regulates molecular movement into and
out of cell Interacts with other cells/environment
6
Genetic material - DNA, found in the nucleus
Cytoplasm Cytosol (the fluid part)
Water Salts Organic monomers and polymers
Organelles
AnimalAnimalCellCell
AnimalAnimalCellCell
PlantPlantCellCell
PlantPlantCellCell
NucleusNucleus
GolgiGolgi
MitochondriaMitochondria
EndoplasmicEndoplasmicReticulumReticulum
CentriolesCentrioles ChloroplastsChloroplasts
AnimalAnimalCellCell
AnimalAnimalCellCell
PlantPlantCellCell
PlantPlantCellCell
NucleolusNucleolus
RibosomesRibosomes
Central VacuoleCentral Vacuole
Smooth E.R.Smooth E.R. Cell WallCell Wall
Protein fibers Give Cell shape; networks of intermediate
filaments Help Cell movement; microfilaments &
microtubules Amoeboid movement Muscle contraction Cell migration during development
Organelle movement & suspension Cyclosis; pathways for vesicle migration
Cell division
MicrotubuleMicrotubule
MicrofilamentsMicrofilaments
IntermediateIntermediateFilamentsFilaments
Actin subunitsActin subunits
Tubulin subunitsTubulin subunits
EndoplasmicReticulum
Mitochondrion
PlasmaMembrane
Tubular extensions of plasma membrane
Movement of fluid, or locomotion Two functionally different types
Cilia: numerous, paddle-like, synchronized Flagella: longer, fewer, more whip-like
Filled with microtubules 9 pairs in periphery; 2 singlets in center “9+2” arrangement (for eukaryotes)
““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
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.
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
Power Stroke Recovery StrokeWater
Scanning E.M.Scanning E.M.of a ciliateof a ciliate
Cell control and genetics Seen Genes in thread-like chromosomes Control production of all proteins
Bounded by nuclear envelope Made up of Double lipid bilayer Pores regulate transport
Not always at center of cell
NucleolusNucleolus
PoresPores
Chromatin ThreadsChromatin Threads(Chromosomes)(Chromosomes) NuclearNuclear
EnvelopeEnvelope
Chromatin – DNA not coiled up into a chromosome
Chromosome – DNA coils around proteins called histones to create linear chromosomes
Contains nucleolus of RNA Site of ribosome assembly
PlasmaPlasmaMembraneMembrane
NucleusNucleus
NuclearNuclearPoresPores
NucleoliNucleoli
NucleusNucleus
Cell WallCell Wall
ChromosomesChromosomes
-made of RNA and protein
- Site of protein synthesis
- Dark granules, (usually drawn as small circles)
Folded membranes attached to nucleus
Rough ER - protein synthesis
Ribosomes chain amino acids into polypeptide
Ribosomes on outside surface of rough ER
Composed of rRNA and proteins
Smooth ER
Lipid synthesis
RibosomesRibosomes
UnitUnitMembraneMembrane
VesiclesVesiclesformingforming
Rough ERRough ERRough ERRough ER
Smooth ERSmooth ERSmooth ERSmooth ER
RibosomesRibosomes
Processes material synthesized by ER Packages material and provides “address
label” Distributes material in sacs called vesicles Some for inside, others outside cell Secretory vesicles merge with cell
membrane Synthesis and transport of
polysaccharides
Material Material ReceivedReceivedFrom ERFrom ER
Material DestinedMaterial Destinedfor Exportfor Export
TEMTEM
Produced by Golgi apparatus
Vesicles containing hydrolytic enzymes
Digestive system of cell
Digest material engulfed by cell
Digest and recycle damaged organelles
LysosomeLysosome
Destined forDestined forExportExport
GolgiGolgiEndoplasmicEndoplasmic
ReticulumReticulum
Destined forDestined forGolgiGolgi
Special kidney-like organelle
Draws water in from cytoplasm & expels it
Important for some single-celled freshwater animals
Requires ATP
1111
2222
Paramecium sp.
Expelling WaterExpelling Waterto Outsideto Outside
ExpandedExpandedwith Waterwith Water
Large, water-filled spaces (cell sap)
Can take up over 90% of cell volume
Surrounded by tonoplast (single membrane)
Functions: Storage of pigments (red/blue), acids,
salts, wastes
Maintain cell pressure (turgor pressure)
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
“Powerhouse” of cell Numerous Glucose catabolism Bounded by double membrane Matrix / cristae Have their own DNA and ribosomes;
self-replicating
CristaeCristaeMatrixMatrix
OuterOuterMembraneMembrane
InnerInnerMembraneMembrane
Green plants only Captures light energy Produces carbohydrate from CO2 and H2O
In cytoplasm of mostly mesophyll cells of leaf
Stroma / grana (thylakoid stacks) Have their own DNA and ribosomes; self-
replicating
ThylakoidsThylakoids
OuterOuterMembraneMembrane
InnerInnerMembraneMembrane
One GranumOne Granum
StromaStroma
Associated w/photosynthesis
Double bilipid membrane
Many functions
Chloroplasts
Storage of pigments
Storage of photosynthetic products
DoubleDoubleBilipidBilipid
MembraneMembrane
StarchStarchGranulesGranules
CapsuleCapsule
Cell WallCell WallPlasmaPlasmaMembraneMembrane
CytosolCytosol
Nucleoid DNANucleoid DNA
FlagellumFlagellum
Plasmid DNAPlasmid DNA
Small (<5 mircometers)
Cytosol, DNA, ribosomes, cell membrane, (usually a cell wall too)
Nucleoid – location of chromosome
Single, circular chromosome
Plasmid – small DNA ring, separate from nucleoid
Flagella with a 9+0 structure (never cillia)
Capsule/slime layer – polysaccharide coatings for protection
Pili – protein jutting out from cell wall
The endThe endThe endThe end