2. Eubacteria “true” bacteria microscopic ex cyanobacteria (blue-green algae) on earth for over...
-
Upload
buck-barnett -
Category
Documents
-
view
217 -
download
0
Transcript of 2. Eubacteria “true” bacteria microscopic ex cyanobacteria (blue-green algae) on earth for over...
2. Eubacteria“true” bacteriamicroscopicex cyanobacteria (blue-green
algae) on earth for over 3 billion years
able to carry out photosynthesis (produces oxygen)
oxygen conc of atmosphere increased allowing oxygen breathers (animals) to survive
Uses of Eubacteriadigestion in intestinesyoghurt/cheese productionfermentation (wine, beer, pickling…)wastewater/oil spill/toxic spill treatmentBiologySourcedecomposers
Dangerous Eubacteriacause health
problems: strep throatfood
poisoning (E. coli and salmonella)
Structure & Function of Bacteria microscopic smallest living
cells classified
according to:1. cell shape2. cell wall
structure3. motility (way of
moving)
1. Cell Shape3 basic cell shapesspherical – “cocci”rod-shaped – “ bacilli”spiral – “spirochetes”
prefixes are added to show living arrangement of bacteria
strepto – chainstphlyo - cluster
CAN YOU NAME IT???
staphylococcus diplococcus
streptococcus
2. Cell Wall Structure2 kinds of cell walls, appear
different when stained with Gram stain
peptidoglycan – thick coat of sugars, makes wall strong & rigid (Gram postive)
less peptidoglycan (Gram negative)
Movementvarious methods:most mobile bacteria use flagella
(whip-like tail)others secrete mucous can glide
on
Typical Bacteria
How Bacteria Reproduce1. Asexual - Binary
Fission1 original cell splits into
2can occur in 20 minutes
for many bacteria species.
In 12 hours, 1 bacterium can divide to form a colony of 68 billion cells.
overcrowding, waste, and food availability do not allow populations to grow this large.
produces colonies of bacteria that are genetically identical.
2. Types of Sexual Reproduction
1. Transformation: bacteria pick up stray DNA from their surroundings.
2. Conjugation: two bacterial cells join (= conjugate) to exchange genetic material (plasmids, separate from main DNA)
3. Transduction: viruses that infect bacteria transmit genetic material from another sourceEndospores form when
environmental conditions make normal functions too difficult.