Monerans virus01
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Transcript of Monerans virus01
Monerans - prokaryotic cellsDo not have a membrane-bound nucleus
• Size is 1-10 micrometers (1 micrometer is 1 thousandth of a millimeter)
• 4 Phyla (old system)
1. Eubacteria - true bacteria, surrounded by cell wall
2. Archaebacteria - live in harsh environments
3. Cyanobacteria - blue-green, photosynthetic
4. Prochlorobacteria - contain chlorophyll, like plants
Identification2. Cell wall - Gram
staining
Gram positive - takes in dye and is violet
Gram negative - appears red. Usually disease causing bacteria.
Chemical differences in cell wall
Identification3. Movement
– Flagella
– Lash, snake or spiral forward
– Glide along slime layer
– No movement at all
Identification4. Obtain energy
Autotrophs - can make own food
a. Phototrophic - traps sunlight
b. Chemotrophic - uses inorganic molecules
Identification
Heterotroph - cannot make own food. Takes in organic molecules, breaks down and absorbs.
Respiration• Obligate aerobes - must have
oxygen
• Obligate anaerobes - does not need oxygen– Tetanus and Clostridium botulinium
• Facultative anaerobes - with or without oxygen
Reproduction
• Binary fission - asexual cell division
• Conjugation - sexual exchange of genetic info
• Spore formation endospore- thick internal wall that encloses DNA. Grows when conditions are right.
Importance of Bacteria
A. Good Bacteria• Production of food
cheese, buttermilk, wine
• Industrial use - digest oil from spills, remove poisons from water, used to synthesize drugs.
• Symbiosis - live with other organisms.
Ex:E. coli in intestines helps absorption
• Nutrient flow - bacteria recycle & decompose dead material to return to soil
• Nitrogen fixation for plants
Importance of Bacteria
B. Bad bacteria• Pathogenic -
disease causing– Diphtheria,
tuberculosis, typhoid fever, tetanus, syphilis, cholera & bubonic plague
Controlling bacteria growth• Freezing - stops
growth
• Refrigeration - slows growth
• Canning - heat to boil, seals out air but some endospores will survive
Controlling bacteria growth
• Drying - no moisture
• Salt - if enough then no growth
• Radiation & alcohol - used to sterilize & kill
• Antibiotics - drugs & natural compounds that attack and destroy
Viruses
A noncellular particle made up of genetic material and protein that
can invade living cells
(a parasite needs a host)
VirusesA. Composed of DNA or RNA (not both!)
surrounded by a capsid (protein coat)
B. Not composed of cells. Infect living cells, grows, reproduces & evolves– Bacteriophage: virus that invades bacteria
C. Shapes– Rod– Tadpole– Many sided (helical or cube-like)
VirusesD. Vary in size (20 - 400 nanometers)
1 nanometer = 1 billionth of a meter
E. Viruses classifed according to host– Bacteria
– Plant viruses
– Human & other animal viruses (HIV & SIV)
F. Viruses mutate and become stronger in next generation
Lytic Virusinvade or infect a living host to
reproduce (kills host)
A. Infection/attachment - injects DNA into host cell
B. Growth - virus DNA shuts down normal cell activities to make copy of itself
C. Replication = uses materials of host to make copies
D. Cell lysis = infected cell bursts & releases new viral particles that will infect other cells
Lysogenic InfectionDoes not lyse the host
cell, it justs incorporates itself in host DNA (prophage)
Ex: Retrovirus - contains RNA. When in host cell, the genetic info is read backwards (RNA to DNA). Some cause cancer.
HIV is a retrovirus
Viral Diseases
• Chicken pox
• Cold sores
• Yellow fever
• Measles
• Common cold
• HIV
• Some forms of cancer (HPV)
Famous People
• Jonas Salk - polio vaccine
• Louis Pasteur - rabies vaccine
• Edward Jenner - small pox vaccine