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