prokaryotes, bacteria, & viruses
DESCRIPTION
PROKARYOTES, BACTERIA, & VIRUSES. By carter reid. Eukaryotes v. Prokaryotes. Prokaryote Characteristics. Single cell No true nucleus F ew organelles Archaebacteria – extreme environments Eubacteria – “normal” bacteria. Eukaryotes v. Prokaryotes. Eukaryotes. Prokaryotes. Smaller - PowerPoint PPT PresentationTRANSCRIPT
PROKARYOTES, BACTERIA, &
VIRUSESBy carter reid
Eukaryotes v. Prokaryotes
Prokaryote Characteristics
Single cellNo true nucleusFew organellesArchaebacteria –
extreme environmentsEubacteria –
“normal” bacteria
Eukaryotes v. ProkaryotesEukaryotes
Larger (up to 100 times!)
More complex Nucleus Have chromosomes Membrane bound
organelles Ex: Animals, plants,
protists
Prokaryotes
Smaller Not as complex No nucleus Have single strand of
DNA and plasmid No membrane bound
organelles Ex: Bacteria
CHARACTERISTICS of Bacteria
Prokaryotes – meaning “before a nucleus”
Divided into 2 domainsBacteriaArchaea
Archaebacteria Dominate in extreme environments 3 types
ThermoacidophilesHot, acidic areas (ex: sulfur hot
springs, thermal vents on ocean floor)Halophiles
Very salty areas, usually aerobic (ex: Great Salt Lake, Dead Sea)
MethanogensNo oxygen (anaerobic) areas, take in
oxygen and give off methane (ex: sewege treatment, swamps, bogs)
EUBACTERIA
Most studied organism Found everywhere, except extreme
environments Very strong cell walls (has
peptidoglycan) Some have a second cell wall
PROKARYOTE STRUCTURE
Genetic material (DNA)
FlagellaPiliRibosomesCapsule
FUNCTION of the Structure
DNA – found in nucleoid (Remember: prokaryotes DO NOT have a nucleus)
Capsule – polysaccharide layer (aka sugar), prevents dry-out, helps attach cell to surfaces, prevents WBC’s from “eating” them
Pili – made of protein, hair-like, also helps attachment, can act as a bridge between cells
Flagella – helps with locomotion (aka movement) Ribosomes – make proteins for the chromosomes
HOW DO WE IDENTIFY BACTERIA??
ShapeCell WallsMovement
SHAPE of Bacteria Cocci – spherical, round shape Bacilli – rod-shaped Spirilli – spiral - shaped Strepto – long chains Staphylo – clumps Diplo - pairs
Let’s Practice…DRAW THE FOLLOWING BACTERIA:1.Staphylococcus2.Streptococcus
Now, write the types from the pictures below…
1.2. 3.
CELL WALLSHave peptiodglycan (made of dissacharides & peptide fragments)
Why is it important for bacteria to have strong cell walls?
MOVEMENT
Some are stationarySome use flagella to move
Bacteria REPRODUCTION Sexual Reproduction – called
ConjugationCells attach and exchange info
Asexual Reproduction – called Binary FissionChromosome replicates, then
separates Can happen every 20 min. Becomes 1 BIL. IN 10 HRS!
METABOLISM of Bacteria Photoautotrophs
Do photosynthesis need light to liveCalled cyanobacteria Release Oxygen into the environment
ChemoautotrophsDo not require lightBreak down & release inorganic compounds
(Nitrogen or Sulfur) and keeps them cycling Aerobes
Require oxygen to grow Anaerobes
Do not require oxygen, use fermentation instead
SURVIVAL Endospores
Dormant cellResistant to harsh conditionsForms around chromosome and
small part of cytoplasmEx: anthrax, botulism, tetanus
MutationsQuick reproduction, so genetic
mutations help survivalLeads to “antibiotic - resistant
bacteria”
ECOLOGY of Bacteria Bacteria are
decomposers and return vital nutrients to the soil/environment
NORMAL FLORA – harmless bacteria in & out of your body E.Coli in your intestines
makes Vitamin K (for blood-clotting)
DIFFERENT from the food poisoning kind
FOOD & MEDICINE Cheese, yogurt,
pickles – made w/the help of bacteria
Used to make CHOCOLATE (bacteria breaks down the cocoa bean covering)
MEDICINE – some anti-biotics (ex: tetracycline) originally made by bacteria
DISEASE –CAUSING Bacteria
Only a small % of bacteria ACTUALLY cause disease
They harm in two ways… Bacteria multiply quickly @
the infection site Bacteria secrete a toxin
that can cause harm (ex: Botulism – paralyzes nervous system cells)
DISEASE –CAUSING Bacteria
PATHOGENS – disease-causing bacteria
ANTIBIOTICS – block the growth & reproduction of bacteria (they break down the cell wall)
How to Control “BAD” Bacteria
STERILIZATION – heat or chemically treat bacteria to kill it Disinfect – chemical solution kills bacteria Refrigerate – bacteria grows slower in the cold Heat/Boil – high temps kill bacteria