THE CELL AND THE CELL AND CELLULAR CELLULAR ENVRIONMENTENVRIONMENT

CellCell Basic structural unit of all plants Basic structural unit of all plants

and animalsand animals A membrane enclosing a thick A membrane enclosing a thick

fluid and a nucleusfluid and a nucleus Specialized to carry out all the Specialized to carry out all the

body’s basic functionsbody’s basic functions

ProcaryotProcaryot Single-cell organismSingle-cell organism BacteriaBacteria StructuresStructures

Cell membraneCell membrane

Cytoplasmic matrixCytoplasmic matrix

NucleoidNucleoid

Cell wallCell wall

Cell MembraneCell Membrane Absolute requirement for all living Absolute requirement for all living

organismsorganisms Cells must interact in a selective Cells must interact in a selective

fashion with their enviornmentfashion with their enviornment Cells must acquire nutrients, eliminate Cells must acquire nutrients, eliminate

waste and maintain their internal waste and maintain their internal environment based on external environment based on external changeschanges

Encompasses the cytoplasmEncompasses the cytoplasm

Cytoplasmic matrixCytoplasmic matrix Lacks organellesLacks organelles Subtance that lies between the plasma Subtance that lies between the plasma

membrane and the nuceloidmembrane and the nuceloid Largely waterLargely water

about 70% of bacterial mass is about 70% of bacterial mass is waterwater

Often packed with ribosomesOften packed with ribosomesmade of protein and RNAmade of protein and RNAprotein synthesis {building of protein synthesis {building of

proteins}proteins}

The nucleoidThe nucleoid Where the DNA is locatedWhere the DNA is located DNA is a single circle, double DNA is a single circle, double

strandedstranded Composed of 60% DNA, some Composed of 60% DNA, some

RNA and a small amount of RNA and a small amount of proteinprotein

Cell WallCell Wall One of the most important parts One of the most important parts

of the procaryotic cellof the procaryotic cell Gives shapeGives shape Protects from osmotic lysisProtects from osmotic lysis

lysis; breaking down of a celllysis; breaking down of a cell

osmosis; movement of waterosmosis; movement of water

Functions of Procaryotic StructuresFunctions of Procaryotic Structures Plasma MembranePlasma Membrane

selectively permeable barrierselectively permeable barrier

mechanical boundarymechanical boundary

nutrient and waste transportnutrient and waste transport

location of many metabolic location of many metabolic processesprocesses

detection of cues for chemotaxisdetection of cues for chemotaxis

ChemotaxisChemotaxis Directed movements according to Directed movements according to

chemicals in their enviornmentchemicals in their enviornment Finding of foodFinding of food

Gas vacuoleGas vacuole

buoyancybuoyancy RibosomesRibosomes

protein synthesisprotein synthesis

Periplasmic spacePeriplasmic space

nutrient processing and uptakenutrient processing and uptake Cell wallCell wall

shapeshape

protection from lysisprotection from lysis Capsules and slime layersCapsules and slime layers

resistance to phagocytosisresistance to phagocytosis

adherence to surfacesadherence to surfaces

PhagocytosisPhagocytosis

Processing of engulfing or eating such as Processing of engulfing or eating such as the immune system consuming or the immune system consuming or destroying pathogensdestroying pathogens

Fimbriae and piliFimbriae and pili

attachement to surfacesattachement to surfaces

matingmating FlagellaFlagella

movementmovement

EndosporeEndospore

survival under harsh survival under harsh environmental environmental conditionsconditions

The CellThe Cell

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Eucaryotic Cell Eucaryotic Cell StructureStructure

Multi-cell organismsMulti-cell organisms

Structures, characteristics and Structures, characteristics and functionsfunctions

Cytoplasmic MatrixCytoplasmic Matrix Endoplasmic ReticulumEndoplasmic Reticulum Golgi ApparatusGolgi Apparatus Lysosomes and endocytosisLysosomes and endocytosis RibosomesRibosomes

MitochondriaMitochondria ChloroplastsChloroplasts Nucleus and cell divisionNucleus and cell division External cell coveringsExternal cell coverings Cilia and flagellaCilia and flagella

Eucaryotic cells contain Eucaryotic cells contain organellesorganelles

OrganelleOrganelle

intracellular structures that intracellular structures that perform perform specific functionsspecific functions

Cytoplasmic matrix Cytoplasmic matrix Featureless, homogenous substanceFeatureless, homogenous substance One of the most important and One of the most important and

complex parts of the cellcomplex parts of the cell The environment of the organellesThe environment of the organelles Location of many important Location of many important

biochemical processesbiochemical processes Several physical changes are due to Several physical changes are due to

matrix functionsmatrix functions

Several physical changes are due to Several physical changes are due to matrix activitymatrix activity

WaterWater A eucaryotic cell is 70 to 85% water A eucaryotic cell is 70 to 85% water

by weightby weight Two formsTwo forms

bulk or free waterbulk or free water

bound water or water of hydrationbound water or water of hydration

Bulk or free waterBulk or free water Osmotically active waterOsmotically active water

Bound waterBound water Bound to the surface of proteinsBound to the surface of proteins Where water, nutrients and waste Where water, nutrients and waste

products can be storedproducts can be stored

MicrofilamentsMicrofilaments StructureStructure MovementsMovements Form the cytoskeleton Form the cytoskeleton

Contain structures such as Contain structures such as flagella, flagella, cilia cilia and lamellipodia.and lamellipodia.

Plays important roles in Plays important roles in transport transport and and division.division.

LamellipodiaLamellipodia Propels the cell across a substratePropels the cell across a substrate

Endoplasmic ReticulumEndoplasmic Reticulum Transport of materialsTransport of materials Protein and lipid synthesisProtein and lipid synthesis

Golgi ApparatusGolgi Apparatus Packaging and secretions of Packaging and secretions of

materials for use within the cellmaterials for use within the cell Lysosome formationLysosome formation

LysosomesLysosomes Intracellular digestionIntracellular digestion

Cells need to make Cells need to make proteinsproteins. Those proteins might be used . Those proteins might be used as enzymes or as support for other cell functions. When as enzymes or as support for other cell functions. When you need to make proteins, you look for ribosomes. you need to make proteins, you look for ribosomes. RibosomesRibosomes are the protein builders or the protein are the protein builders or the protein synthesizerssynthesizers of the cell. They are like construction guys of the cell. They are like construction guys who connect one amino acid at a time and build long who connect one amino acid at a time and build long chains. chains.

Ribosomes are found in many places around the cell. You Ribosomes are found in many places around the cell. You might find them floating in the might find them floating in the cytoplasm (cytoplasm (cytosolcytosol)). Those . Those floating ribosomes make proteins that will be used inside floating ribosomes make proteins that will be used inside of the cell. Other ribosomes are found on the of the cell. Other ribosomes are found on the endoplasmic reticulumendoplasmic reticulum. Endoplasmic reticulum with . Endoplasmic reticulum with attached ribosomes is called rough. It looks bumpy under attached ribosomes is called rough. It looks bumpy under a microscope. Those attached ribosomes make proteins a microscope. Those attached ribosomes make proteins that will be used inside the cell and proteins made for that will be used inside the cell and proteins made for export out of the cell. export out of the cell.

Intracellular digestionIntracellular digestion Breaking down of large molecules Breaking down of large molecules

into smaller onesinto smaller ones

MitochondriaMitochondria ““powerhouse” of the cellpowerhouse” of the cell Energy productionEnergy production

ChloroplastsChloroplasts PhotosynthesisPhotosynthesis

NucleusNucleus Ribosomal RNA synthesisRibosomal RNA synthesis Ribosome constructionRibosome construction