CELLSCELLS

Structure and FunctionStructure and Function

Cell = smallest unit of lifeCell = smallest unit of life

Two Major Cell Types Two Major Cell Types

Cell TypeCell Type ExampleExample

ProkaryoticProkaryotic BacteriaBacteria

EukaryoticEukaryotic ProtistsProtistsFungiFungiPlantsPlantsAnimalsAnimals

Prokaryotic CellProkaryotic Cell

Eukaryotic CellEukaryotic Cell(protist, animal)(protist, animal)

Eukaryotic CellEukaryotic Cell(plant)(plant)

Differences Between Cell TypesDifferences Between Cell Types Prokaryotic CellProkaryotic Cell Eukaryotic CellEukaryotic Cell

Single circular Single circular chromosomechromosome

Multiple linear Multiple linear chromosomeschromosomes

Chromosome found Chromosome found in a cytoplasmic in a cytoplasmic region called the region called the nucleoid.nucleoid.

Chromosomes found Chromosomes found in a membrane-in a membrane-bound nucleus.bound nucleus.

No internal No internal membranesmembranesSome infolded Some infolded plasma membraneplasma membrane

Extensive network of Extensive network of internal membranes internal membranes

Common ComponentsCommon Components and Cellular Organization and Cellular Organization

• Plasma MembranePlasma Membrane– boundary surrounding the cellboundary surrounding the cell

• Genetic material: DNAGenetic material: DNA– located in a membrane-bound nucleus located in a membrane-bound nucleus

for eukaryotic cellsfor eukaryotic cells• CytoplasmCytoplasm

– Semi-fluid matrix containing enzymes Semi-fluid matrix containing enzymes and organellesand organelles (enzyme = biological catalyst)(enzyme = biological catalyst)

• CytoskeletonCytoskeleton– network of filaments and tubules in cytoplasm network of filaments and tubules in cytoplasm

that maintains cell shape, allows movement that maintains cell shape, allows movement

Features of Features of Prokaryotic Cells Prokaryotic Cells All prokaryotic cells containAll prokaryotic cells contain

Structure Structure FunctionFunctionPlasma Plasma MembraneMembrane

Regulates flow of Regulates flow of substances into and out substances into and out of cellof cell

NucleoidNucleoid Cytoplasmic region Cytoplasmic region containing genetic containing genetic materialmaterial

CytoplasmCytoplasm Cytosol: fluidCytosol: fluidRibosomesRibosomesEnzymesEnzymes

Features of Features of Prokaryotic Cells Prokaryotic Cells

Other possible prokaryotic structuresOther possible prokaryotic structures

Structure Structure FunctionFunctionCell WallCell Wall Supports cellSupports cell

Maintains shapeMaintains shape

CapsuleCapsule Protects from dryingProtects from dryingProtects against Protects against white blood cellswhite blood cells

Infolded Plasma Infolded Plasma MembranesMembranes

MetabolismMetabolismCell divisionCell division

Features of Features of Prokaryotic Cells Prokaryotic Cells

Other possible prokaryotic structuresOther possible prokaryotic structures

Structure Structure FunctionFunctionBacterial Bacterial Flagellum Flagellum

MovementMovement

PlasmidPlasmid Small circular DNA Small circular DNA Replicates Replicates independently independently

Applying Your KnowledgeApplying Your Knowledge

In bacterial cellsIn bacterial cells• where is the genetic material located? where is the genetic material located? • which one is used for movement?which one is used for movement?• which one provides structural support which one provides structural support

for the cell?for the cell?

1.1. Cell WallCell Wall2.2. Flagellum Flagellum 3.3. CapsuleCapsule4.4. PlasmidPlasmid5.5. NucleoidNucleoid

Functions of Eukaryotic Cell FeaturesFunctions of Eukaryotic Cell Features

Structure Structure Function(s)Function(s)Plasma Plasma Membrane Membrane

1. Regulates passage of 1. Regulates passage of materials into and out of cellmaterials into and out of cell

2. Cell-Cell Recognition2. Cell-Cell Recognition

Functions of Eukaryotic Cell FeaturesFunctions of Eukaryotic Cell Features

Structure Structure Function(s)Function(s)Cell WallCell Wall(protists, (protists, fungi, plants)fungi, plants)

1.1. Controls cell shape, Controls cell shape, protects, supportsprotects, supports

Functions of Eukaryotic Cell FeaturesFunctions of Eukaryotic Cell Features Structure Structure Function(s)Function(s) NucleusNucleus 1.1. Carrier of genetic materialCarrier of genetic material

DNA + protein = chromatinDNA + protein = chromatin2. Governs cell activities2. Governs cell activities3. Directs cell reproduction3. Directs cell reproduction4.4. Surrounded by Membrane Surrounded by Membrane

= nuclear envelope= nuclear envelope5.5. Contains nucleolus—Contains nucleolus—

produces ribosomesproduces ribosomeswhich synthesize proteinswhich synthesize proteins

Functions of Functions of Eukaryotic Eukaryotic

Cell FeaturesCell Features

Structure Structure Function(s)Function(s)Rough Rough Endoplasmic Endoplasmic Reticulum (RER)Reticulum (RER)

1.1. Associated ribosomes produce Associated ribosomes produce proteins proteins

2.2. Prepares proteins for exportPrepares proteins for exportSmooth Smooth Endoplasmic Endoplasmic Reticulum (SER)Reticulum (SER)

1.1. Lipid SynthesisLipid Synthesis2.2. Drug detoxificationDrug detoxification3.3. Transport of proteins from RERTransport of proteins from RER

RERRER SERSER

Functions of Eukaryotic Functions of Eukaryotic Cell Features Cell Features

Structure Structure Function(s)Function(s)Golgi Golgi ApparatusApparatus

Collects, modifies, packages and Collects, modifies, packages and distributes proteins and lipids from ERdistributes proteins and lipids from ER

Functions of Functions of Eukaryotic Eukaryotic

Cell FeaturesCell Features

Structure Structure Function(s)Function(s)LysosomeLysosome Contains digestive enzymes Contains digestive enzymes

to digest food in protists or to digest food in protists or destroy aging organelles destroy aging organelles

Endomembrane SystemEndomembrane SystemRough Rough

Endoplasmic Endoplasmic ReticulumReticulum

Smooth Smooth Endoplasmic Endoplasmic

ReticulumReticulum

VesicleVesicle

Golgi Golgi ApparatusApparatus

VesicleVesicle

LysosomeLysosome

VesicleVesicle

Plasma Plasma MembraneMembrane

Functions of Functions of Eukaryotic Eukaryotic

Cell FeaturesCell Features

Structure Structure FunctionFunctionPeroxisomePeroxisome Removes harmful oxidants Removes harmful oxidants

from cells from cells

Functions of Functions of Eukaryotic Cell Eukaryotic Cell

FeaturesFeatures

Structure Structure FunctionFunction

MitochondrionMitochondrion Captures energy from Captures energy from organic molecules, organic molecules, producing ATPproducing ATP

Functions of Functions of Eukaryotic Cell Eukaryotic Cell

FeaturesFeatures

Structure Structure FunctionFunctionChloroplastChloroplast(protists, plants)(protists, plants)

Photosynthesis: Uses light Photosynthesis: Uses light energy to produce organic energy to produce organic moleculesmolecules

Functions Functions of Eukaryotic of Eukaryotic Cell FeaturesCell Features

Structure Structure Function(s)Function(s)CytoskeletonCytoskeleton 1.1. Maintains cell shapeMaintains cell shape

2.2. Anchors organelles and proteinsAnchors organelles and proteins3.3. Allows for organelle movement Allows for organelle movement

and cellular movement in some and cellular movement in some cell typescell types

Functions of Functions of Eukaryotic Cell Eukaryotic Cell

FeaturesFeatures

Structure Structure FunctionFunctionCentrioleCentriole Gives rise to basal bodies that Gives rise to basal bodies that

produce cilia or flagella produce cilia or flagella

Functions of Functions of EukaryEukaryotic Cell otic Cell

FeaturesFeaturesStructure Structure Function(s)Function(s)VacuoleVacuole 1.1. Central vacuole (plants) stores Central vacuole (plants) stores

waste, maintains turgidity.waste, maintains turgidity.2.2. Contractile vacuole (protists) Contractile vacuole (protists)

maintains water balance.maintains water balance.3.3. Food vacuole (protists) fuses with Food vacuole (protists) fuses with

lysosome for digestion.lysosome for digestion.

Functions of EukaryoticFunctions of Eukaryotic Cell Features Cell Features

Structure Structure Function(s)Function(s)Cilia and Cilia and Flagella Flagella

1.1. Move substances across Move substances across cell surface in lungs, cell surface in lungs, fallopian tubesfallopian tubes

2.2. Cell movement in sperm, Cell movement in sperm, protistsprotists

Applying Your KnowledgeApplying Your Knowledge

A.A. Which organelle produces proteins that Which organelle produces proteins that will be exported from the cell? will be exported from the cell?

B.B. Which organelle contains digestive Which organelle contains digestive enzymes?enzymes?

C.C. Which site acts as a protein packaging Which site acts as a protein packaging and distribution center?and distribution center?

1.1. CiliumCilium2.2. Rough ER Rough ER 3.3. Golgi apparatusGolgi apparatus4.4. Smooth ERSmooth ER5.5. LysosomeLysosome

Thought QuestionsThought Questions

1.1. What are similarities forWhat are similarities fora. eukaryotic and prokaryotic cells?a. eukaryotic and prokaryotic cells?b. animal and plant cells?b. animal and plant cells?

2. 2. What are differences betweenWhat are differences betweena. eukaryotic and prokaryotic cells?a. eukaryotic and prokaryotic cells?b. animal and plant cells?b. animal and plant cells?

AnalogyAnalogy

If the cell were a factory If the cell were a factory

the ____________________ would be the ____________________ would be (name a cell component)(name a cell component)

a _____________________________.a _____________________________. (name a part of a factory)(name a part of a factory)

Part of CellPart of Cell Part of FactoryPart of FactoryCapsuleCapsule Security GateSecurity Gate

Cell WallCell Wall Outer Fence around the factoryOuter Fence around the factory

ChloroplastChloroplast Solar PanelSolar Panel

CytoskeletonCytoskeleton Moving Belt where items are inspectedMoving Belt where items are inspectedSteel Support, Interior WallsSteel Support, Interior Walls

Cilia/FlagellaCilia/Flagella Conveyor Belt, Elevator/EscalatorConveyor Belt, Elevator/Escalator

EnzymeEnzyme Worker; Assemblage MachineryWorker; Assemblage Machinery

Golgi ComplexGolgi Complex Distribution/Packaging DepartmentDistribution/Packaging DepartmentMailroomMailroom

MitochondrionMitochondrion Generator, Engine Room, Power SourceGenerator, Engine Room, Power Source

NucleoidNucleoid Storage of pre-production materialStorage of pre-production material

NucleusNucleus Supervisor’s Office, BossSupervisor’s Office, BossCorporate Office, Central OperationsCorporate Office, Central Operations

Plasma MembranePlasma Membrane Loading/Unloading Dock, Inner Wall, DoorLoading/Unloading Dock, Inner Wall, Door

RibosomesRibosomes Assembly Line TrackAssembly Line Track

RERRER Production LineProduction Line

SERSER Shipping DockShipping Dock

VacuoleVacuole Storage AreaStorage Area

Cellular InteractionsCellular Interactions

Signal Transduction: passing a signal Signal Transduction: passing a signal from the cell surface to the interiorfrom the cell surface to the interior First messenger binds to First messenger binds to

Cell Surface Receptor Cell Surface Receptor Receptor signals nearby Receptor signals nearby

Regulator ProteinRegulator Protein Regulator activates Regulator activates

nearby enzyme nearby enzyme Enzyme catalyzes formationEnzyme catalyzes formation

of Second Messenger of Second Messenger Second Messenger initiatesSecond Messenger initiates

Cellular Response Cellular Response

Cellular InteractionsCellular Interactions Cell Adhesion: joining of cells Cell Adhesion: joining of cells

controlled by proteins called controlled by proteins called Cellular Adhesion Molecules Cellular Adhesion Molecules (CAMS)(CAMS)

important in important in InfInflammatory Responselammatory Response Placenta FormationPlacenta Formation Learning and MemoryLearning and Memory

Lack of cell adhesion is Lack of cell adhesion is implicated in cancer implicated in cancer and arthritis.and arthritis.