Eukaryotes vs ProkaryotesAnd Bacteria
SBI 3C: OCTOBER 2012
BACTERIA CLASSIFICATIONCan be classified into 2 kingdoms:
Eubacteria Archaebacteria
Similarities: Unicellular Prokaryotic Single chromosome Reproduce asexually by binary fission Thrive in moist environments
Dr. Oz – Toilet bacteria: http://www.youtube.com/watch?v=CljhLb1Ar9UMythbusters: http://www.youtube.com/watch?v=dQgVn3AvJ8A
CELL TYPES2 TYPES OF CELLS:
Eukaryotic: Has a true nucleus surrounded by nuclear membrane Ex. Plants and animal cells
Prokaryotic: Does not have its chromosomes surrounded by nuclear
membrane Ex. Bacterial cells
PROPERTIES: NUCLEUS
PROPERTY EUKARYOTES PROKARYOTES
DNA •USUALLY 46 CHROMOSOMES•FOUND IN NUCLEUS
•SINGLE CHROMOSOME•SINGLE LOOP
TRUE NUCLEUS •PRESENT •ABSENT
NUCLEAR MEMBRANE
•PRESENT •ABSENT
PROPERTIES: ORGANELLESPROPERTY EUKARYOTES PROKARYOTES
INTERNAL ORGANELLES
•COMPLEX •MANY
•VERY FEW•SIMPLE ORGANELLES
RIBOSOMES •LARGER •SMALLER
CELL WALL •FOUND IN PLANTS, ALGAE AND FUNGI
•PRESENT
MITOCHONDRIA •PRESENT •ABSENT
PLASTIDS •CHLOROPLASTS IN PLANTS AND ALGAE
•ABSENT
FLAGELLA •COMPLEX TAILS INVOLVED IN MOVEMENT, FEEDING AND SENSING
•SIMPLE
PROPERTIES: FUNCTIONSPROPERTY EUKARYOTES PROKARYOTES
MOVEMENT •COMPLEX FLAGELLA, CILIA, CYTOPLASMIC STREAMING
•SINGLE FLAGELLA GLIDING
REPRODUCTION •MITOSIS •BINARY FISSION•CONJUGATION
EVOLUTION •APPEARED 1.5 BILLION YEARS AGO
•APPEARED 3.5 BILLION YEARS AGO
METABOLISM •LOWER METABOLIC RATE, LOWER GROWTH RATE AND THUS GREATER GENERATION TIME
•HIGHER METABOLIC RATE, HIGHER GROWTH RATE AND THUS A SHORTER GENERATION TIME
PROPERTIES: SIZE AND EXAMPLES
PROPERTY EUKARYOTES PROKARYOTES
SIZE •USUALLY >2UM DIAMETER
•USUALLY <2UM DIAMETER
EXAMPLES •PLANTS•ANIMALS•PARAMECIUM
•E COLI•BACILLUS ANTHRACIS
ARCHAEBACTERIAThrive under extreme conditionsThree major groups:
Thermophiles: Live in extremely hot environments (hot springs)
Methanogens: Grow on carbon dioxide and hydrogen gas to produce
methane Live in deep sea vents and intestines of mammals (ex.
humans) Halophiles:
Live in extremely salt environments (salt flats)
EUBACTERIABest known example: Escherichia Coli (E. Coli)
Flagella: used for movement
Pili: hair-like structures, help bacteria attach to each other
Genetic material floats in cytoplasmRibosomes: make protein
Cytoplasm
Cell membraneCell wall
Capsule: sticky coating that protects them from immune systems
Dr. Oz – Toilet bacteria: http://www.youtube.com/watch?v=CljhLb1Ar9UMythbusters: http://www.youtube.com/watch?v=TeAOC3A0xJ8&feature=related
EUBACTERIA: CELL WALLCan identify bacteria based on cell wallEubacteria contain polymer peptidoglycan in
cell wallDifferences in amount of peptidolgycan
determine staining of bacterial cell
gram positive gram negative
BACTERIA
Stained with crystal violet dye (purple)
Fixed with Gram’s iodine
Decolourized with ethanol
Stained with safranin (red)
STAINING THE CELL WALL
Gram-positive bacteria retain crystal violet and appear purpleEx. Staph
Gram-negative bacteria ethanol washes out crystal violet so they stain red with safranin and appear pinkish redEx. E coli
EUBACTERIA: SHAPE AND CONFIGURATION
SHAPES: Spherical Rod Spiral
CONFIGURATION: Cocci (singular: coccus) Bacilli (singular: bacillus) Spirilla (singluar: spirillum) All form pairs, cluster colonies or chains of cells
Spherical Rod Spiral
EUBACTERIA: NUTRITION AND RESPIRATION
RESPIRATION: Some are aerobic (need oxygen to survive)
TB bacteria Some are anaerobic (only grow without oxygen)
Tetanus, botulism Some can grow with or without oxygen
E Coli
NUTRITION: Autotrophs: make their own food
Photosynthetic (energy from sun), chemisynthetic (energy from chemical reactions)
Heterotrophs: obtain nutrients from other organisms
EUKARYOTIC REPLICATION:Eukaryotic cells replicate by mitosis
PROKARYOTIC REPRODUCTION:Reproduce asexually by binary fission
CONJUGATION: Donor and recipient bacteria make cell to cell
contact by sex pilus Plasmids (genetic info) are exchanged resulting in
altered characteristics
BACTERIAL DISEASESNAME SYMPTOMS BACTERIAL SHAPE
Pnuemonia Clogs up lungs Cocci
Salmonella (from food)
Vomiting, diarrhea Bacillus
Cholera (from water supply)
Diarrhea, cramps Bacillus
Tetanus Convulsions Motile bacillus
Tuberculosis Infects lungs, fever, weight loss
Bacillus
Leprosy Skin lesions, decay of extremities
Bacillus
Gonorrhea Penal discharge, painful urination
Diplococcus
TREATMENT AND PREVENTION:Bacterial diseases can be treated using
antibioticsAntibiotics are chemicals toxic to bacteria
which are produced commonly by plants and fungi Eg. Penicillin (from the fungus penicillium)
Bacterial diseases could be prevented using vaccines Substances which stimulate your body to produce
antibodies to the bacterium even though you are not infected
BACTERIAL GROWTH:Lag Phase:
Adjust to environment
Exponential Growth: 24816
Stationary Phase Stable, just enough
food or spaceDeath
Running out of nutrients