structureof prokaryotic eukary
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Nucleus vs nucleoid DNA : circular vs linear, presence of histonesMembranous organellesCell wall-peptidoglycanCell division: binary vs mitosisRibosomes: 70S vs 80SCytoskeleton
CocciDiplococciStreptococciTetradsSarcinaeStaphylococci
CoccobacilliDiplobacilliStreptobacilli
Vibrio-curved rodsSpirilla-helical & rigidSpirochetes-helical & flexibleOther shapesPleomorphic
Glycolipids or glycoproteinsSurrounds cell Capsule or slime layerCapsule more organized & attached to wallAdvantages of capsule
Surrounds cellLoosely organized & not attachedTangled mass of fibers-dextranAttachment to surfaces -S. mutansShields bacteria from immune defense &
antibiotics
Animal cells have oneMade of carbohydratesNo do not have a cell wallSurround plasma membraneStabilizes PM
MovementSpins like propellerClockwise or counter clockwise
Chemotaxis- movement toward or away
Monotrichous: one at endAmphitrichous: both endsLophotrichous: tuft at end or endsPeritrichous: around the cell
Composition-protein subunits: flagellin (H protein) E. coli H7Chains twisted together with hollow coreHelical shapedFilament, hook, basal bodyHookBasal body:
Basal body
Classified by flagella protein
SpirochetesTreponema pallidum-syphilisBorrelia burgdorferi-Lyme disease
Bundle of fibrials within a sheathCorkscrew motion
Flagella & cilia
9+2 arrangement of microtubules
Cilia in Paramecium & respiratory cells
Made of pilin: string of subunits
Function: attachment
Few to hundredsFimbrae
Pili-longer & fewer
Not in eukaryotes
Function
Basis of Gram stain
PeptidoglycanRepeating subunits of disaccharides
N-acetyl glucosamine (NAG) N-acetyl muramic acid (NAM)Linked alternately in rows
Attached by polypeptidesTetrapeptide side chains link NAM subunitsCross bridge of amino acids link tetrapeptides
Forms lattice
Confers shape & prevents lysisCell growth
Autolysins break cross linkages in peptidoglycan
Transpeptidases seal breaksPenicillin inactivates these enzymes
Existing cellsTreat with lysozyme-tears, saliva etc.Destroys linkages between carbohydrates
Thick layers: 40-80% of dry wt, up to 30 layers
Contains teichoic acidAlcohol and phosphateNegative charge
Cell growth-prevents lysisAntigenic properties
Few layers of peptidoglycan- 10%Outer membrane: bilayer
Periplasm
Strong negative charge
Barrier to some antibiotics
Outer membrane-endotoxinO polysaccharidesLipid-lipid A
Penicillin:
Lysozyme:
Differential stain dev by Hans Gram 1880sClassifies bacteria into 2 groupsBased upon cell wall compositionGram variable stain unevenly
Gram non reactive do not stain or stain poorly
Gram positives
ETOH disrupts outer layerCV-I complex is washed out of thin
peptidoglycan layerCounterstain
Streptococci
Mycobacteria
MycoplasmaPM unique with sterols protect from lysis
Lack a cell wall so pleomorphicClassified with gram positivesSmallest genome of any bacteria
Droplet spread-use regular maskWhy can’t you use penicillin?
Simpler than prokaryotes Algae & plantsFungiYeastsProtozoa
Animals
Thin, fluid structure inside cell wall-viscousProteins
Phospholipids-2 layers
Selective permeabilityPassive transport:Active transport: Enzymes break down nutrientsInfoldings
Phospholipids and proteinsCarbohydrates and sterols-cholesterolMore rigid than prokaryotic PMEndocytosis
Exocytosis
80% water, thick, solutesInflux of water, increase in osmotic pressure
on membraneRigid cell wall prevents lysis
Contains DNARibosomesInclusion bodies
Cytosol-fluid portionCytoskelton
Microfilaments: Microtubules:
Intermediate filaments:Cytoplasmic streaming
Single, ds DNA chromosomeAttached to PM at some pointNucleoid area, not a nucleusPlasmids
Largest structure in cell
Nucleoli
DNA associated with proteins -histones
2 subunits of protein and rRNA70s ribosomesPolyribosomes-chainsProtein synthesisAntibiotics inhibit protein synthesis
Polysaccharide granules
Sulfur granules
Reserve deposits-volutin (phosphates)
Unique to bacteria: Clostridium & BacillusSporulation-formation of spores
Triggered by damage to coatEnzymes break down endosporeWater enters & metabolism beginsNot a reproductive structure
Unique to eukaryotesMembranous structures
Endoplasmic reticulumSmooth & rough
Golgi complexLysosomesMitochondriaCloroplasts
Flattened membranous sacsRough ER-ribosomes attached
Smooth ER- no ribosomes
Free ribosomes- proteins don’t need processing
Stacks of membranous sacsReceive transport vesicles from ERModify molecules to form glycoproteins,
glycolipids lipoproteins Transported in secretory vesicles to PM or to
outside cell
Formed from GolgiContain digestive enzymes: proteases &
nucleasesBreak down old parts of cellBreaks down pathogens
Double membrane
Generation of ATP
Thylakoids-flattened membranous sacs
Contain DNA 70s ribosomesStroma thick fluid in center- Calvin cycleGeneration of ATP & sugars