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Stromatolites been around 3.2 billion years.
diverse cause of the horizontal gene transfer.
successful in reproduction
Prokaryotes can live in extreme environment.
salt/ hot/ methane. they have cell walls for survival.
the cell wall keeps it from bursting (lyse) in a hypertonic environment. (water lost inhibits reproduction).
Cell walls are made of a mesh called Peptidoglycan (polysaccharides and peptides/proteins).
Peptidoglycan: thick layer (gram positive) cell turns purple. thin layer (gram negative) cell turns pink.
Pencillin makes holes in the cell walls, cause the cells to die.
shapes of prokaryotes:
Bacillus (rods), Coccus (grape) and Spiral or helical (comma).
Capsule (cover cell walls) and Pili makes the bacteria sticky. some pili are
made for gene transfer.
reproduction binary fisson is super fast in bacteria (20 minutes).
another way to
reproduce is spores, they can last in extreme temp. and dehydrations. allows bacteria to become dormant. autoclaves.
- prokaryotes have
- Ribosomes. antibiotics kills bacteria by preventing translation of protein-
- more slective for the bacterial ribosomes.
- get food :
- autotrophs, phototrophs and heterotrophs.
- air: obligate
- aerobes/ obligate anaerobes/ facultative anaerobes.
cyanobacterium that forms filamentous colonies. cells are either photosynthetic(sugar)
or heterocysts (nitrogen). biofilm is a coat of colony of bacteria.
Archaea: ribosomal rna, archaea have introns. bacterial cells contain
peptidoglycan. multiple rnaa and histones in archae ( closely related to
- halophiles (salt)
- thermophiles (heat)
- methanogens (methane producers)
- found in dead sea and the great salt lake.
- live in very hot water, wuch as hot springs or hydrothermal vents. 100+.
- gives off matheane as a waste product. Lives in swamps(anaerobic) digestive
- tracts of animals.
Archaea are very common in the oceans.
VERY diverse. (gene transfer)
Divided by: proteobacteria , chlamydias, spirochetes, gram-positive bacteria,
- example: rhizobium, salmonella, vibrio cholera, e. coli, helicobacter pylori.
- Chlamydia trachomatis.
- bacteria- mycobacterium tuberculosis, strptomycetes, staphylococcus,
- is believed to be the ancestor of cholorplast.
How does bacteria cause diseases?
Damage the tissues by (endotoxins/exotoxins)
- Endotoxins- outer
- membranes of gram negative bacteria. Toxins in to bloodstreams, trigger a
- massive immune response.
- Exotoxin- released by
- bacterial cells. Botulinum toxin is the
- worst one out there. Exotoxin can cause disease even if the bacteria is dead.