CELLSCELLS

Organization of Living OrganismsOrganization of Living Organisms

Hooke

English philosopher

Used primitive microscopes under coarse adjustment to view specimens.

Coined the term “cell” in the 1600’s

LEUWENHOEKLEUWENHOEKAnton Von Leuwenhoek studied pond water Anton Von Leuwenhoek studied pond water

to observe its living contentsto observe its living contents

SCHLEIDEN & SCHWANNSCHLEIDEN & SCHWANNMattias Schleiden and Theodore Schwann Mattias Schleiden and Theodore Schwann

determined the first point of the cell theory: determined the first point of the cell theory: All organisms are made up of cellsAll organisms are made up of cells

Cell TheoryCell Theory

1.1. ALL organisms are made of one or more ALL organisms are made of one or more cellscells

2.2. The cell is the basic unit of structure and The cell is the basic unit of structure and function of living thingsfunction of living things

3.3. ALL cells arise from preexisting cellsALL cells arise from preexisting cells

Cells specialize and Cells specialize and are grouped into are grouped into tissuestissues

Different tissues Different tissues combine to form combine to form organsorgans

Several organs form Several organs form systems to carry out systems to carry out life functions life functions

Prokaryotic vs. EukaryoticProkaryotic vs. EukaryoticSmallSmall

Simple Simple

No nucleus (DNA/RNA float No nucleus (DNA/RNA float in cell)in cell)

GrowGrow

Reproduce Reproduce

Respond to environmentRespond to environment

Ex: bacteriaEx: bacteria

LargeLarge

ComplexComplex

Have nucleus (contains Have nucleus (contains DNA/RNA)DNA/RNA)

Have organellesHave organelles

GrowGrow

ReproduceReproduce

Respond to environmentRespond to environment

Ex: plants, animals, fungi, Ex: plants, animals, fungi, insects etcinsects etc

Cells = The basic structure of life!Cells = The basic structure of life!

Cells have specific structures that perform Cells have specific structures that perform specific jobs called ORGANELLES specific jobs called ORGANELLES

Organelles are floating in the jellylike Organelles are floating in the jellylike substances in the cell called CYTOPLASMsubstances in the cell called CYTOPLASM

OrganellesOrganelles1.1. NucleusNucleus2.2. MitochondriaMitochondria3.3. VacuolesVacuoles4.4. RibosomesRibosomes5.5. Endoplasmic ReticulumEndoplasmic Reticulum6.6. LysosomeLysosome7.7. Golgi BodyGolgi Body8.8. Cell MembraneCell Membrane9.9. ChloroplastChloroplast10.10. Cell WallCell Wall11.11. CiliaCilia12.12. FlagellumFlagellum13.13. CentrioleCentriole

bacteriacellsbacteriacells

Types of cellsTypes of cells

animal cellsanimal cells plant cellsplant cells

Prokaryote- no organelles

Eukaryotes- organelles

Cell size comparisonCell size comparison

Bacterial cell

Animal cell

micron = micrometer = 1/1,000,000 meter diameter of human hair = ~20 microns

most bacteria 1-10 microns

eukaryotic cells 10-100 microns

Why study cells?Why study cells?Cells Cells Tissues Tissues Organs Organs Bodies Bodies bodies are made up of cellsbodies are made up of cells cells do all the work of life!cells do all the work of life!

What jobs do cells have to do for an organism to live…What jobs do cells have to do for an organism to live… ““breathe” breathe”

gas exchange: Ogas exchange: O22 in vs. CO in vs. CO22 out out

eateattake in & digest foodtake in & digest food

make energymake energyATPATP

build moleculesbuild moleculesproteins, carbohydrates, fats, nucleic acidsproteins, carbohydrates, fats, nucleic acids

remove wastes remove wastes control internal conditionscontrol internal conditions

homeostasishomeostasis respond to external environmentrespond to external environment build more cellsbuild more cells

growth, repair, reproduction & developmentgrowth, repair, reproduction & development

The Work of LifeThe Work of Life

ATP

Cells have 3 main jobsCells have 3 main jobs make energymake energy

need energy for all activitiesneed energy for all activities

need to clean up waste produced need to clean up waste produced while making energywhile making energy

make proteinsmake proteinsproteins do all the work in a cell, proteins do all the work in a cell, so we need lots of themso we need lots of them

make more cellsmake more cellsfor growthfor growth

to replace damaged or diseased cellsto replace damaged or diseased cells

The Jobs of CellsThe Jobs of Cells

Our organellesdo all thesejobs!

ATP

OrganellesOrganellesOrganelles do the work of cellsOrganelles do the work of cells each structure has a job to doeach structure has a job to do

keeps the cell alive; keeps you alivekeeps the cell alive; keeps you alive

Model Animal Cell

They’re likemini-organs!

1. Cells need power1. Cells need power!!

Making energyMaking energy to fuel daily life & growth, the cell must…to fuel daily life & growth, the cell must…

take in food & digest ittake in food & digest it

take in oxygen (Otake in oxygen (O22))

make ATPmake ATP

remove wasteremove waste organelles that do this work…organelles that do this work…

cell membrane cell membrane

lysosomeslysosomes

vacuoles & vesicles vacuoles & vesicles

mitochondriamitochondria

ATP

FunctionFunction separates cell from outsideseparates cell from outside controls what enters or leaves cellcontrols what enters or leaves cell

OO22, CO, CO22, food, H, food, H22O, nutrients, wasteO, nutrients, waste recognizes signals from other cellsrecognizes signals from other cells

allows communication between cellsallows communication between cells

StructureStructure double layer of fatdouble layer of fat

phospholipid bilayerphospholipid bilayer receptor moleculesreceptor molecules

proteins that proteins that receive signalsreceive signals

Cell membraneCell membrane

lipid “tail”

phosphate“head”

Vacuoles & vesiclesVacuoles & vesiclesFunctionFunction moving material moving material

around cellaround cell storagestorage

StructureStructure membrane sacmembrane sac

small foodparticle

vesicle

vacuole filled w/ digestive enzymes

vesicle filled w/ digested nutrients

Food & water storageFood & water storage

plant cellsplant cells

contractilevacuole contractilevacuole

animal cellsanimal cells

central vacuole central vacuole

food vacuole food vacuole

FunctionFunction make ATP energy from cellular respirationmake ATP energy from cellular respiration

sugar + Osugar + O22 ATP ATP

fuels the work of lifefuels the work of life

StructureStructure double membranedouble membrane

MitochondriaMitochondria

in both animal & plant cellsin both animal & plant cells

ATP

MitochondriaMitochondria make energy from sugar + Omake energy from sugar + O22

cellular respirationcellular respiration

sugar + Osugar + O2 2 ATP ATP

ChloroplastsChloroplasts make energy + sugar from sunlightmake energy + sugar from sunlight

photosynthesisphotosynthesis

sunlight + COsunlight + CO22 ATP & sugar ATP & sugar ATP = active energyATP = active energy sugar = stored energysugar = stored energy

build leaves & roots & fruit build leaves & roots & fruit out of the sugarsout of the sugars

Plants make energy two waysPlants make energy two ways!!

ATP

sugar

ATP

Mitochondria are in both cellsMitochondria are in both cells!!!!

2. Cells need workers = 2. Cells need workers = proteinsproteins!!

Making proteinsMaking proteins to run daily life & growth, the cell must…to run daily life & growth, the cell must…

read genes (DNA)read genes (DNA)build proteinsbuild proteins

structural proteins (muscle fibers, hair, skin, claws)structural proteins (muscle fibers, hair, skin, claws) enzymes (speed up chemical reactions)enzymes (speed up chemical reactions) signals (hormones) & receptorssignals (hormones) & receptors

organelles that do this work…organelles that do this work…nucleus nucleus ribosomesribosomesendoplasmic reticulum (ER) endoplasmic reticulum (ER) Golgi apparatusGolgi apparatus

Proteins do all the work! Proteins do all the work!

cellsDNA proteins

one of the major job of cells is to make proteins,because…one of the major job of cells is to make proteins,because…

proteins do all the work!proteins do all the work!

signals

structural

enzymes

receptors

NucleusNucleusFunctionFunction control center of cellcontrol center of cell protects DNAprotects DNA

instructions for building proteinsinstructions for building proteins

StructureStructure nuclear membranenuclear membrane nucleolusnucleolus

ribosome factoryribosome factory chromosomeschromosomes

DNADNA

Ribosomes on ER

Ribosomes Ribosomes FunctionFunction protein factoriesprotein factories read instructions to build proteins from DNAread instructions to build proteins from DNA

StructureStructure some some freefree in cytoplasm in cytoplasm some some attachedattached to ER to ER

FunctionFunction works on proteinsworks on proteins

helps complete the helps complete the proteins after ribosome proteins after ribosome builds thembuilds them

makes membranesmakes membranes

StructureStructure rough ERrough ER

ribosomes attachedribosomes attachedworks on proteinsworks on proteins

smooth ERsmooth ERmakes membranesmakes membranes

Endoplasmic ReticulumEndoplasmic Reticulum

transport vesicles

vesiclescarrying proteins

FunctionFunction finishes, sorts, labels & ships proteinsfinishes, sorts, labels & ships proteins

like UPS headquarters like UPS headquarters shipping & receiving departmentshipping & receiving department

ships proteins in vesiclesships proteins in vesicles““UPS trucks”UPS trucks”

StructureStructure membrane sacsmembrane sacs

Golgi ApparatusGolgi Apparatus

DNA

RNA

ribosomes

endoplasmicreticulum

vesicle

Golgi apparatus

vesicle

proteinon its way!

protein finishedprotein

Making Proteins

TO:

TO:

TO:

TO:

nucleus

central vacuolestorage: food, water or waste

mitochondriamake ATP in cellular respiration

chloroplastmake ATP & sugars in photosynthesis

cell wallsupport

cell membranecell boundarycontrols movementof materials in & out

recognizes signals

Golgi apparatusfinish & ship proteins

nucleuscontrol cellprotects DNA

endoplasmic reticulumprocesses proteinsmakes membranes

lysosomedigestion & clean up

ribosomesmake proteinscytoplasm

jelly-like material around organelles

nucleolusmake ribosomes

3. Cells need to make more 3. Cells need to make more cellscells!!

Making more cellsMaking more cells to to replacereplace, , repairrepair & & growgrow, ,

the cell must…the cell must…copy their DNAcopy their DNAmake extra organellesmake extra organelles

divide the new DNA & new divide the new DNA & new organelles between 2 new organelles between 2 new “daughter” cells“daughter” cells

organelles that do this work…organelles that do this work…nucleus nucleus centriolescentrioles

CentriolesCentriolesFunctionFunction help coordinate cell divisionhelp coordinate cell division

only in animal cellsonly in animal cells

StructureStructure one pair in each cellone pair in each cell

cell membranecell boundarycontrols movementof materials in & out

recognizes signals

cytoplasmjelly-like material holding organelles in place

mitochondriamake ATP energy

from sugar + O2

nucleusprotects DNAcontrols cell

ribosomesbuilds proteins

ERhelps finish proteinsmakes membranes

Golgi apparatusfinishes, packages & ships proteins

lysosomefood digestiongarbage disposal &recyclingvacuole & vesicles

transport inside cellsstorage

centriolescell division

Cells have 3 main jobsCells have 3 main jobs make energymake energy

need food + Oneed food + O22

cellular respiration & photosynthesiscellular respiration & photosynthesis

need to remove wastesneed to remove wastes make proteinsmake proteins

need instructions from DNAneed instructions from DNA

need to chain together amino acids & “finish” need to chain together amino acids & “finish” & “ship” the protein& “ship” the protein

make more cellsmake more cellsneed to copy DNA & divide it up to daughter cellsneed to copy DNA & divide it up to daughter cells

Cell SummaryCell Summary

Our organellesdo all thosejobs!

DiffusionMove from HIGH to LOW concentration directly through

membranesimple diffusion

no energy needed help through a protein

channelfacilitated diffusion (with help)

no energy needed

HIGH

LOW

DIFFUSIONDIFFUSION

Collisions between molecules cause them Collisions between molecules cause them to continually spread apartto continually spread apart

Movement occurs until molecules are Movement occurs until molecules are equally distributed = equally distributed = EQUILIBRIUMEQUILIBRIUM

Simple vs. facilitated diffusion

inside cell

outside cell

lipidinside cell

outside cell

H2O

simple diffusion facilitated diffusion

H2O

protein channel

Active TransportActive Transport

Movement of molecules from Movement of molecules from low to highlow to high concentration (riding a bike uphill)concentration (riding a bike uphill)

Must use Must use ENERGY or ATPENERGY or ATP to move to move moleculesmolecules

Move in and out until the molecules reach Move in and out until the molecules reach EQUALIBRIUMEQUALIBRIUM

OsmosisOsmosis

Diffusion of Diffusion of WATERWATER across a cell across a cell membranemembrane

HighHigh to to lowlow concentration concentration

Cells are 98% water and 2% dissolved Cells are 98% water and 2% dissolved mineralsminerals

OsmosisOsmosis

If the liquid that surrounds the cell has the If the liquid that surrounds the cell has the samesame concentration of water as the cytoplasm no net concentration of water as the cytoplasm no net diffusion occurs in either direction (molecules diffusion occurs in either direction (molecules move at equal rates)move at equal rates)

If the water concentration is If the water concentration is low low and solute is and solute is highhigh the cell membrane will shrink the cell membrane will shrink

If the water concentration is If the water concentration is highhigh and solute is and solute is lowlow the cell membrane will expand.. Cell will the cell membrane will expand.. Cell will burstburst

OsmosisOsmosis

If the liquid outside of the cell has a high If the liquid outside of the cell has a high concentration of water (less solute) than concentration of water (less solute) than the cytoplasm, water will diffuse into the the cytoplasm, water will diffuse into the cellcell

If the liquid outside of the cell has a lower If the liquid outside of the cell has a lower concentration of water (more solute) than concentration of water (more solute) than the cytoplasm water will diffuse out of the the cytoplasm water will diffuse out of the cellcell

Keeping Water Balance

Cell survival depends on balancing water uptake & water loss