Download Bacteria

Bacteria
By
Diana L. Duckworth
Rustburg High School
Campbell County
Differences with Eukaryotes
http://bhs.smuhsd.org/bhsnew/a
cademicprog/science/vaughn/St
udent%20Projects/Paul%20&%
20Marcus/Cell_Replication.html
• Prokaryotes – no internal cell organization
• Eykaryotes are 10 x larger than prokaryotes
• No true multicellular bacteria – cells not
specialized
• Single strand of DNA (circular); eukarya linear
• Reproduction by binary fission – cell just
pinches in two; lengthy process in Eukarya
• Flagella are more simple; also have pilli
• Can be either aerobic or anerobic; more
diversity in types of metabolism
3 shapes of bacteria
• Bacillus (rod)
• Coccus (round)
• Spirillum (spiral)
http://sciences.unlv.edu/desertsurvivors/Pages/episode2.htm
Two types of Cell Wall
• Distinguished by
staining
– Gram Positive
– Gram Negative
• Determines
susceptibility to
antibiotics
Staphylococcus aureus
Pink – Gram negative
Blue – Gram positive
http://library.med.utah.edu/kw/derm/pages/in06_5.htm
How bacteria obtain energy
http://user.uni-frankfurt.de/~schauder/cyanos/cyanos.html
• Autotrophs
– Photosynthesis – use light to fix
carbon
• Some are obligate anerobes,
others aerobes
• Cyanobacteria – source of
oxygen in atmosphere.
– Chemosynthesis – energy from
ammonia, hydrogen sulfide,
methane
– Important in nitrification (ammonia
to nitrate)
• Heterotrophs – important
decomposers of dead organisms
– Rhizobium – nitrogen fixing
bacteria in roots of legumes
(nitrogen to nitrate)
– Gangrene
http://abdellab.sunderland.ac.uk/lectures/Parmacology/ANSdoc/serotonin8.html
Bacterial Pathogens – humans are food
Anthrax – air borne
http://srs.dl.ac.uk/Annual_Reports/AnRep01_02/anthrax.htm
Vector - fleas
http://webs.wichita.edu/mschneegurt/biol103/lecture14/lectur
e14.html
http://health.usnews.com/articles/health/2008/01/03
/12-diseases-that-altered-history/photos/
Bubonic
Plague
www.acponline.org/graphics/bioterro/u_ec.jpg
http://www.jyi.org/features/ft.php?id=102
Lyme Disease
http://gracelings.blogspot.com/2007_07_01_archive.html
Bacterial Toxins (food & water)
Tuberculoses
http://sudanwatch.blogspot.com/2006/03/adrawater-capacity-improvement-in.html
Botulism
Cholera
http://anthropik.com/2006/12/industria
l-agriculture-the-e-coli-outbreak/
E. coli
http://www.wnysmart.org/botulism.htm
http://letsgoeverywhere.wordpress.com/2007/11/
19/i-survived-cholera-epidemic-2007/
Fighting Bacterial Infections
• Prevention – hygene; especially in food
preparation
• Antibiotics – During WWII – huge advancement
– Alexander Fleming – Penicillium (fungus) secretes
penicillin
– Different antibiotics effective against different cellular
processes
• Problem – antibiotic resistance; mutations
spontaneous & spread
– Favored by misuse of antibiotics – stopping treatment
when feel good, not going entire course
– Prescribing antibiotics when not effective (e.g.
viruses)
– Benign bacteria can develop mutation & share it with
pathogenic bacteria
Useful Bacteria
• Natural in foods – yogurt, cheese, pickles,
sourdough bread, buttermilk, etc.
• Genetically engineered to produce
important compounds
• Engineered to clean up environmental
contamination – oil spills
• Engineered to concentrate low grade ores