Cells and Tissues. Carry out all chemical activities needed to sustain life Carry out all chemical activities needed to sustain life Cells are the building.

Cells and TissuesCells and Tissues

Cells and TissuesCells and Tissues

Carry out all chemical activities needed to Carry out all chemical activities needed to sustain lifesustain life

Cells are the building blocks of all living Cells are the building blocks of all living thingsthings

Tissues are groups of cells that are similar Tissues are groups of cells that are similar in structure and functionin structure and function

For Example: muscle tissueFor Example: muscle tissue

Anatomy of the CellAnatomy of the Cell

Cells are not all the sameCells are not all the sameAll cells share general structuresAll cells share general structuresAll cells have three main regionsAll cells have three main regions

NucleusNucleusCytosol (cytoplasm)Cytosol (cytoplasm)Plasma membranePlasma membrane

The NucleusThe Nucleus

Control center of the cellControl center of the cellContains genetic material (DNA)Contains genetic material (DNA)

Three regionsThree regionsNuclear envelopeNuclear envelope (membrane) (membrane)NucleolusNucleolus (plural nucleoli) (plural nucleoli)ChromatinChromatin (DNA coiled around protein – (DNA coiled around protein –

protein acts as support for fragile DNA)protein acts as support for fragile DNA)

The NucleusThe Nucleus

The Nucleus continued…The Nucleus continued…Nuclear envelopeNuclear envelope ( or ( or

nuclear membrane) nuclear membrane) Barrier of the nucleus; Barrier of the nucleus;

separates in from outseparates in from outConsists of a double Consists of a double

membranemembraneContains nuclear pores Contains nuclear pores

that allow for exchange that allow for exchange of material with the rest of material with the rest of the cellof the cell

The Nucleus continued….The Nucleus continued….

NucleoliNucleoli Nucleus contains one Nucleus contains one

or more nucleolior more nucleoli Sites of ribosome Sites of ribosome

productionproduction Ribosomes move into Ribosomes move into

the cytoplasm through the cytoplasm through nuclear poresnuclear pores

NucleolusNucleolus

The Nucleus continued….The Nucleus continued….ChromatinChromatin

Composed of DNA and proteinComposed of DNA and protein Present when the cell is not dividingPresent when the cell is not dividing Scattered throughout the nucleusScattered throughout the nucleus Coils and shortens to form chromosomes when the cell Coils and shortens to form chromosomes when the cell

divides (protects fragile DNA during cell separation)divides (protects fragile DNA during cell separation)

Plasma MembranePlasma MembraneBarrier for cell contentsBarrier for cell contentsControls what exits and enters the cell through Controls what exits and enters the cell through

osmosis and diffusionosmosis and diffusionAlso contains proteins, cholesterol, and Also contains proteins, cholesterol, and

glycoproteins (proteins with sugar attached)glycoproteins (proteins with sugar attached)

Plasma MembranePlasma Membrane

Membrane StructurePLAY

Plasma Membrane Plasma Membrane SpecializationsSpecializations

MicrovilliMicrovilli Finger-like projections Finger-like projections

that increase surface that increase surface area for absorptionarea for absorption

Microvilli are present Microvilli are present in our intestines; helps in our intestines; helps absorp nutrients and absorp nutrients and water we consume by water we consume by eatingeating

Cytoplasm or CytosolCytoplasm or Cytosol

Cytoplasm is the material outside the Cytoplasm is the material outside the nucleus and inside the plasma membrane nucleus and inside the plasma membrane

It’s the fluid that all organelles are It’s the fluid that all organelles are suspended insuspended in

CytoplasmCytoplasm

Contains three major elementsContains three major elementsCytosolCytosol

Fluid that suspends other elements (jello)Fluid that suspends other elements (jello)

OrganellesOrganelles machinery of the cell machinery of the cell ““Little organs” that perform functions for the cellLittle organs” that perform functions for the cell

InclusionsInclusions Chemical substances such as stored nutrients or Chemical substances such as stored nutrients or

cell products like wastecell products like waste

Cytoplasmic OrganellesCytoplasmic Organelles

Cytoplasmic OrganellesCytoplasmic OrganellesMitochondriaMitochondria

““Powerhouses” of the cellPowerhouses” of the cell Change shape continuouslyChange shape continuously Carry out reactions where oxygen is used to break Carry out reactions where oxygen is used to break

down fooddown food Provides energy for cellProvides energy for cell

Cytoplasmic OrganellesCytoplasmic OrganellesRibosomesRibosomes

Made of protein and RNAMade of protein and RNASites of protein productionSites of protein productionFound at two locationsFound at two locations

Free in the cytoplasmFree in the cytoplasm On Rough EROn Rough ER

Cytoplasmic OrganellesCytoplasmic Organelles

Endoplasmic reticulum (ER)Endoplasmic reticulum (ER)Fluid-filled tubes for carrying substancesFluid-filled tubes for carrying substancesTwo types of ERTwo types of ER

Rough endoplasmic reticulumRough endoplasmic reticulum Covered with ribosomesCovered with ribosomes Makes proteins Makes proteins

Smooth endoplasmic reticulumSmooth endoplasmic reticulum Functions in lipid and steroid production and also Functions in lipid and steroid production and also

detoxifies drugs and pesticides that invade the celldetoxifies drugs and pesticides that invade the cell

Rough Endoplasmic Rough Endoplasmic ReticulumReticulum

Ribosome

Protein

Protein insidetransport vesicle

Transportvesicle buds off

mRNA

Rough ER

As the protein is synthesizedon the ribosome, it migratesinto the rough ER cistern.

In the cistern, the protein foldsinto its functional shape. Shortsugar chains may be attachedto the protein (forming aglycoprotein).

The protein is packaged in atiny membranous sac called atransport vesicle.

The transport vesicle buds fromthe rough ER and travels to theGolgi apparatus for furtherprocessing or goes directly tothe plasma membrane where itscontents are secreted.

Cytoplasmic OrganellesCytoplasmic Organelles

Golgi apparatusGolgi apparatus Modifies and packages Modifies and packages

proteinsproteins Produces different types of Produces different types of

packagespackages Secretory vesiclesSecretory vesicles Cell membrane componentsCell membrane components LysosomesLysosomes

Extracellular fluid

Plasma membrane

Golgi vesicle containingmembrane componentsfuses with the plasmamembrane

Golgi vesicle containingdigestive enzymesbecomes a lysosome

Proteins in cisterna

Lysosome fuses withingested substances

Membrane

Transportvesicle

Pathway 3

Pathway 2

Secretory vesicles Pathway 1

Golgiapparatus

Golgi vesicle containingproteins to be secretedbecomes a secretoryvesicle

Cisterna

Rough ER

Proteins

Secretion byexocytosis

LysosomesLysosomes Contain enzymes that digest worn-out or nonusable Contain enzymes that digest worn-out or nonusable

materials within the cellmaterials within the cell

Cytoplasmic OrganellesCytoplasmic OrganellesPeroxisomesPeroxisomes

Membranous sacs of Membranous sacs of oxidase enzymesoxidase enzymes

Detoxify harmful Detoxify harmful substances such as substances such as alcohol, hydrogen alcohol, hydrogen peroxide and peroxide and formaldehydeformaldehyde

Break down free Break down free radicals (highly radicals (highly reactive chemicals)reactive chemicals)

Network of protein structures that extend Network of protein structures that extend throughout the cytoplasmthroughout the cytoplasm

Provides the cell with an internal framework Provides the cell with an internal framework which keeps the cell 3-Dimensionalwhich keeps the cell 3-Dimensional

CytoskeletonCytoskeleton

CellularCellular ProjectionsProjectionsNot found in all cellsNot found in all cellsUsed for movementUsed for movement

Cilia move materials Cilia move materials across the cell surfaceacross the cell surface

Located in the Located in the respiratory system to respiratory system to move mucus move mucus

Flagella propel the cell Flagella propel the cell The only flagellated The only flagellated

cell in the human cell in the human body is spermbody is sperm