The CellThe CellAll Living things are composed of All Living things are composed of cellscells

All Cells have/contain the following:All Cells have/contain the following:

Cell Membrane - Lipid BilayerCell Membrane - Lipid Bilayer - Separates inside from outside - Separates inside from outside

CytoplasmCytoplasmCytoplasmCytoplasm - everything but - everything but DNA/NucleusDNA/Nucleus

Two Cell typesTwo Cell types

        ProkaryoticProkaryotic Cells Cells1.1.            Primitive cells – include bacteriaPrimitive cells – include bacteria

2.2.          No nucleusNo nucleus

3.3.          No Membrane-bound organellesNo Membrane-bound organelles

4.4.          Very Small 1-10 micrometersVery Small 1-10 micrometers

5.5.          Single Strand of Circular “naked” DNASingle Strand of Circular “naked” DNA

6.6.          Contain Contain RibosomesRibosomes

Typical Prokaryotic Typical Prokaryotic CellCell

All Your Base Are Belong To Us

EukaryoticEukaryotic CellsCells

EukaryoticEukaryotic Cells Cells

1.1. 1.1.            Contain a Contain a NucleusNucleus which protects DNA / which protects DNA / ChromosomesChromosomes

2.2. 2.2.          Much larger than prokaryotic cellsMuch larger than prokaryotic cells

3.3. 3.3.          Have many different types of Have many different types of Membrane boundMembrane bound organellesorganelles - - compartmentalization = efficiencycompartmentalization = efficiency

Eukaryotic CellsEukaryotic Cells

Animal Animal Eukaryotic CellEukaryotic Cell

Plant Eukaryotic Plant Eukaryotic CellCell

OrganelleOrganelless

Membrane-Bound organelles only Membrane-Bound organelles only found in found in EukaryotesEukaryotes

Localize Chemical Reactions Localize Chemical Reactions making the cell far more efficientmaking the cell far more efficient

Major Organelles of the Eukaryotic CellMajor Organelles of the Eukaryotic Cell

The The NucleusNucleus““eukaryotic” means “true eukaryotic” means “true nucleus”nucleus”

Contains & protects the Contains & protects the cell’s DNAcell’s DNAHelps coordinate the Helps coordinate the division of cellsdivision of cells

Surrounded by a Surrounded by a Nuclear Nuclear EnvelopeEnvelopeEnvelope is double layered Envelope is double layered with with an an Inner & Outer Inner & Outer membranemembrane

Has perforations called Has perforations called Nuclear PoresNuclear Pores which allow which allow large molecules to pass large molecules to pass in/out of the nucleusin/out of the nucleus

Contains a Contains a NucleolusNucleolusRibosomesRibosomes are made in are made in this regionthis region

Contains DNA packaged in Contains DNA packaged in structures called structures called chromosomeschromosomes

ChromosomChromosomeses

MitochondrMitochondriaia

Serves as the Serves as the “powerhouse “powerhouse of the cell” by of the cell” by generating generating chemical chemical energyenergy

Has it’s own Has it’s own DNA*DNA*

Can divide on Can divide on its own*its own*

Chloroplasts (Plant Cell Only)Chloroplasts (Plant Cell Only)Is the “cell’s farm” - Is the “cell’s farm” - meaning food is meaning food is generated here.generated here.

Does this by Does this by photosynthesisphotosynthesis - - the conversion of the conversion of COCO22, H, H22O and O and

sunlight into sugarsunlight into sugar

Contain Contain ChlorophyllChlorophyll - a - a green pigment - green pigment - which does thiswhich does this

Has it’s own DNA*Has it’s own DNA*

Can divide on its Can divide on its own*own*

Ribosomes

Are NOT Are NOT membrane-bound & membrane-bound & also exist in also exist in prokaryotesprokaryotes

Are used to Are used to manufacture manufacture proteinsproteins

Granular in Granular in appearanceappearance

Often found on Often found on “rough” “rough” endoplasmic endoplasmic reticulumreticulum**

Endoplasmic ReticulumEndoplasmic ReticulumAre folds of Are folds of membranes used to membranes used to package & modify package & modify proteins made by proteins made by ribosomes. They ribosomes. They also make lipidsalso make lipids

2 types2 types““RoughRough” - which ” - which is usually near is usually near nucleus and nucleus and covered with covered with ribosomes giving ribosomes giving it its “rough” it its “rough” appearance. appearance. (Finishes proteins)(Finishes proteins)

““SmoothSmooth” - which ” - which is usually away is usually away from the nucleus from the nucleus (produce lipids)(produce lipids)

Examples of Endoplasmic Examples of Endoplasmic ReticulumReticulum

Smooth ERSmooth ER Rough ERRough ER

Golgi Golgi BodiesBodies

Are the post offices of Are the post offices of the cellthe cell

Modify (address) Modify (address) proteins & lipids and proteins & lipids and send them in send them in packages (packages (vessiclesvessicles) ) throughout (or out of) throughout (or out of) the cell.the cell.

LysosomesLysosomesSmall Vessicles which serve to digest particles and clean-up cellsContain Lysozyme – a powerful digestive enzymeDigests food particlesDestroys worn-out organellesSelf-Destructs worn-out cells

CentriolesCentrioles(Animal Cell Only)(Animal Cell Only)

Serve as Serve as construction/organization construction/organization points for cellular points for cellular microtubulesmicrotubulesOrganize and transfer Organize and transfer chromosomes and other chromosomes and other organelles during Meiosis & organelles during Meiosis & MitosisMitosisOccur in some prokaryotes, Occur in some prokaryotes, protists & animals. Do not protists & animals. Do not occur with fungi and plantsoccur with fungi and plantsTube like structures usually Tube like structures usually at right angles to each at right angles to each other.other.Some animals have Some animals have centriole-like structures at centriole-like structures at the base of flagella called the base of flagella called basal bodiesbasal bodies..

TonoplastTonoplast(water vacuole)(water vacuole)(plant cells only)(plant cells only)

Large HLarge H22O / Lipid / O / Lipid /

waste storage tankwaste storage tank

Provides pressure Provides pressure ((Turgor pressureTurgor pressure) to ) to maintain cell maintain cell structurestructure

Cell WallCell WallProvides support / Provides support / protection for protection for plant cellplant cell

Two layers of cell Two layers of cell wallwall

Primary Cell Primary Cell WallWall – Outer – – Outer – CelluloseCellulose only only

Secondary Cell Secondary Cell WallWall – Inner – – Inner – Cellulose & Cellulose & LigninLignin

Cell membrane is Cell membrane is innermost layerinnermost layer

CytoskeletoCytoskeletonn

Network of fibers Network of fibers which help organize which help organize the internal the internal arrangement within arrangement within cells.cells.Three basic types of Three basic types of fibers compose fibers compose cytoskeleton:cytoskeleton:

Actin FilamentsActin Filaments Thinnest fibers ~7nMThinnest fibers ~7nM Formed from protein Formed from protein

ActinActin

MicrotubulesMicrotubules Largest component Largest component

of cytoskeleton ~25 of cytoskeleton ~25 nMnM

Formed from protein Formed from protein TubulinTubulin

Intermediate Intermediate filamentsfilaments

Intermediate in size Intermediate in size and can varyand can vary

Form from several Form from several proteins inluding proteins inluding vimentinvimentin & & keratinkeratin