Structureof Prokaryotic Eukary

Nucleus vs nucleoid
DNA : circular vs linear, presence of histones
Membranous organelles
Cell wall-peptidoglycan
Cell division: binary vs mitosis
Ribosomes: 70S vs 80S
Cytoskeleton

Cocci
Diplococci
Streptococci
Tetrads
Sarcinae
Staphylococci

Coccobacilli
Diplobacilli
Streptobacilli

Vibrio-curved rods
Spirilla-helical & rigid
Spirochetes-helical & flexible
Other shapes
Pleomorphic

Glycolipids or glycoproteins
Surrounds cell
Capsule or slime layer
Capsule more organized & attached to wall
Advantages of capsule

Surrounds cell
Loosely organized & not attached
Tangled mass of fibers-dextran
Attachment to surfaces - S. mutans
Shields bacteria from immune defense & antibiotics

Animal cells have one
Made of carbohydrates
No do not have a cell wall
Surround plasma membrane
Stabilizes PM

Movement
Spins like propeller
Clockwise or counter clockwise
Chemotaxis- movement toward or away

Monotrichous: one at end
Amphitrichous: both ends
Lophotrichous: tuft at end or ends
Peritrichous: around the cell

Composition-protein subunits: flagellin (H protein) E. coli H7
Chains twisted together with hollow core
Helical shaped
Filament, hook, basal body
Hook
Basal body:

Basal body
Classified by flagella protein

Spirochetes
Treponema pallidum-syphilis
Borrelia burgdorferi-Lyme disease
Bundle of fibrials within a sheath
Corkscrew motion

Flagella & cilia
9+2 arrangement of microtubules
Cilia in Paramecium & respiratory cells

Made of pilin : string of subunits
Function: attachment
Few to hundreds
Fimbrae
Pili-longer & fewer
Not in eukaryotes

Function
Basis of Gram stain

Peptidoglycan
Repeating subunits of disaccharides
N-acetyl glucosamine (NAG)
N-acetyl muramic acid (NAM)
Linked alternately in rows
Attached by polypeptides
Tetrapeptide side chains link NAM subunits
Cross bridge of amino acids link tetrapeptides
Forms lattice

Confers shape & prevents lysis
Cell growth
Autolysins break cross linkages in peptidoglycan
Transpeptidases seal breaks
Penicillin inactivates these enzymes
Existing cells
Treat with lysozyme-tears, saliva etc.
Destroys linkages between carbohydrates

Thick layers: 40-80% of dry wt, up to 30 layers
Contains teichoic acid
Alcohol and phosphate
Negative charge
Cell growth-prevents lysis
Antigenic properties

Few layers of peptidoglycan- 10%
Outer membrane: bilayer
Periplasm

Strong negative charge
Barrier to some antibiotics
Outer membrane-endotoxin
O polysaccharides
Lipid-lipid A

Penicillin:
Lysozyme:

Differential stain dev by Hans Gram 1880s
Classifies bacteria into 2 groups
Based upon cell wall composition
Gram variable stain unevenly
Gram non reactive do not stain or stain poorly

Gram positives

ETOH disrupts outer layer
CV-I complex is washed out of thin peptidoglycan layer
Counterstain

Streptococci
Mycobacteria
Mycoplasma
PM unique with sterols protect from lysis

Lack a cell wall so pleomorphic
Classified with gram positives
Smallest genome of any bacteria
Droplet spread-use regular mask
Why can’t you use penicillin?

Simpler than prokaryotes
Algae & plants
Fungi
Yeasts
Protozoa
Animals

Thin, fluid structure inside cell wall-viscous
Proteins
Phospholipids-2 layers

Selective permeability
Passive transport:
Active transport:
Enzymes break down nutrients
Infoldings

Phospholipids and proteins
Carbohydrates and sterols-cholesterol
More rigid than prokaryotic PM
Endocytosis
Exocytosis

80% water, thick, solutes
Influx of water, increase in osmotic pressure on membrane
Rigid cell wall prevents lysis
Contains DNA
Ribosomes
Inclusion bodies

Cytosol-fluid portion
Cytoskelton
Microfilaments:
Microtubules:
Intermediate filaments:
Cytoplasmic streaming

Single, ds DNA chromosome
Attached to PM at some point
Nucleoid area, not a nucleus
Plasmids

Largest structure in cell
Nucleoli
DNA associated with proteins -histones

2 subunits of protein and rRNA
70s ribosomes
Polyribosomes-chains
Protein synthesis
Antibiotics inhibit protein synthesis

Polysaccharide granules
Sulfur granules
Reserve deposits-volutin (phosphates)

Unique to bacteria: Clostridium & Bacillus
Sporulation-formation of spores

Triggered by damage to coat
Enzymes break down endospore
Water enters & metabolism begins
Not a reproductive structure

Unique to eukaryotes
Membranous structures
Endoplasmic reticulum
Smooth & rough
Golgi complex
Lysosomes
Mitochondria
Cloroplasts

Flattened membranous sacs
Rough ER-ribosomes attached
Smooth ER- no ribosomes
Free ribosomes- proteins don’t need processing

Stacks of membranous sacs
Receive transport vesicles from ER
Modify molecules to form glycoproteins, glycolipids lipoproteins
Transported in secretory vesicles to PM or to outside cell

Formed from Golgi
Contain digestive enzymes: proteases & nucleases
Break down old parts of cell
Breaks down pathogens

Double membrane
Generation of ATP

Thylakoids-flattened membranous sacs
Contain DNA 70s ribosomes
Stroma thick fluid in center- Calvin cycle
Generation of ATP & sugars

Structureof Prokaryotic Eukary

by Deepika Tripathi

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Structureof Prokaryotic Eukary Presentation Transcript