prokaryotes, bacteria, & viruses by carter reid. eukaryotes v. prokaryotes
TRANSCRIPT
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
Thermoacidophiles
Hot, acidic areas (ex: sulfur hot springs, thermal vents on ocean floor)
Halophiles
Very salty areas, usually aerobic (ex: Great Salt Lake, Dead Sea)
Methanogens
No 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.Staphylococcus
2.Streptococcus
Now, write the types from the pictures below…
1.2. 3.
CELL WALLS
Have 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 live
Called cyanobacteria
Release Oxygen into the environment
Chemoautotrophs
Do not require light
Break 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 cell
Resistant to harsh conditions
Forms around chromosome and small part of cytoplasm
Ex: anthrax, botulism, tetanus
MutationsQuick reproduction, so genetic
mutations help survival
Leads 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