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Viruses and Viruses and MoneraMoneraJessica JonesJessica Jones
Spring 2007Spring 2007
What do these diseases have What do these diseases have in common?in common?
Measles http://www.idph.state.il.us/images/measles.jpg
Mumps http://www.kcom.edu/faculty/chamberlain/Website/lectures/lecture/IMAGE/MUMPS.GIF
Polio http://www.immune.org.nz/site_resources/Professionals/Diseases/Polio/Polio.jpg
Hepatitis B http://www.idph.state.il.us/images/hepatitisb.jpg
It looks alive, acts alive… It looks alive, acts alive… but its not!but its not!
Viruses are Viruses are notnot living things. They differ living things. They differ from living things in several ways:from living things in several ways: They need to be inside a living organism to They need to be inside a living organism to
reproduce themselves.reproduce themselves. Outside the cell, they have no metabolism.Outside the cell, they have no metabolism. They do not have cell parts. (i.e. nucleus, They do not have cell parts. (i.e. nucleus,
mitochondria, etc)mitochondria, etc) They are composed of only a nucleic acid They are composed of only a nucleic acid
(DNA or RNA) inside a protein capsule.(DNA or RNA) inside a protein capsule.
Structure of a VirusStructure of a Virus
http://www.humanillnesses.com/images/hdc_0001_0001_0_img0008.jpg
DNA
(or RNA)
Protein capsid
Tube
Tail Fiber
http://mrsec.wisc.edu/Edetc/technologist/thumbnails/Matt/Virus_diagram.jpg
http://www.aidsactioncoalition.org/images/hiv_virus.gif
Viral ReproductionViral Reproduction In order to reproduce:In order to reproduce:
A virus attaches to a host cell.A virus attaches to a host cell. The virus injects the cell with its nucleic acid.The virus injects the cell with its nucleic acid. The viral nucleic acid commands the cell to make more The viral nucleic acid commands the cell to make more
viral protein and nucleic acid.viral protein and nucleic acid. The cell then ruptures, releasing hundreds of new The cell then ruptures, releasing hundreds of new
viruses.viruses.
http://porpax.bio.miami.edu/~cmallery/150/gene/sf11x1virus.jpg
No, they aren’t from the No, they aren’t from the 70’s.70’s. RetrovirusesRetroviruses
These are viruses that store their genetic These are viruses that store their genetic information as RNA.information as RNA.
Example: HIVExample: HIV
http://international.ucla.edu/cms/images/hiv_virus.jpg
How it How it works……works……
http://hiv.buffalo.edu/./images/hiv_virus_in_action.jpg
Kingdom Monera…your Kingdom Monera…your friendly bacteria.friendly bacteria. Bacteria are living, unicellular prokaryotes.Bacteria are living, unicellular prokaryotes. Divided into two kingdoms: Eubacteria and Divided into two kingdoms: Eubacteria and
ArchaebacteriaArchaebacteria Heterotroph or autotroph (most use Heterotroph or autotroph (most use
chemosynthesis).chemosynthesis). Types of Bacteria are classified based on Types of Bacteria are classified based on
their shape, type of cell wall, and their shape, type of cell wall, and movement.movement.
Bacteria have three basic shapes:Bacteria have three basic shapes: Bacilli – rod-shapedBacilli – rod-shaped Cocci – sphericalCocci – spherical Spirilla – spiral Spirilla – spiral
http://fig.cox.miami.edu/~cmallery/150/proceuc/c27x3proc_shapes.jpg
Structure of a BacteriaStructure of a BacteriaCell membrane
Cell wall
Ribosomes
DNA
http://www.ou.edu/class/pheidole/General%20Bacteria.jpg
Eubacteria have peptidoglycan and certain Eubacteria have peptidoglycan and certain specialized lipids in their cells walls that are not specialized lipids in their cells walls that are not present in Archaebacteria.present in Archaebacteria.
Gram staining is used to differentiate types of Gram staining is used to differentiate types of Eubacteria. Eubacteria. Those having thick cell walls will absorb more of the Those having thick cell walls will absorb more of the
dye and appear dark purple (Gram positive).dye and appear dark purple (Gram positive). Those having thinner cell walls will absorb less of Those having thinner cell walls will absorb less of
the dye and appear pink (Gram negative).the dye and appear pink (Gram negative).
http://bioweb.uwlax.edu/bio203/s2008/jaedike_alic/grainpositive.jpg http://www.asm.org/Division/c/photo/gc1.JPG
Bacteria Growth and Bacteria Growth and ReproductionReproduction Bacteria reproduce in two main Bacteria reproduce in two main
ways:ways: Binary fission – when a bacteria grows Binary fission – when a bacteria grows
to double its original size, it copies its to double its original size, it copies its DNA and divides, producing two DNA and divides, producing two identical cells.identical cells.
Conjugation – a hollow bridge is Conjugation – a hollow bridge is formed between 2 bacteria and genes formed between 2 bacteria and genes are transferred from one cell to the are transferred from one cell to the other.other. This creates genetic diversity within the This creates genetic diversity within the
population.population. Spore formation – when conditions are Spore formation – when conditions are
unfavorable (lack of food, drought) that unfavorable (lack of food, drought) that encloses its DNA and part of its encloses its DNA and part of its cytoplasm in a spore.cytoplasm in a spore. When conditions are better, the spore When conditions are better, the spore
will germinate, and the bacterium will will germinate, and the bacterium will continue to grow.continue to grow.
http://porpax.bio.miami.edu/~cmallery/150/gene/sf9x3box.jpg
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/69091a.jpg
We’re not all bad….We’re not all bad…. Bacteria are most widely known for Bacteria are most widely known for
causing diseases such as strep throat, causing diseases such as strep throat, tetanus, meningitis, and tuberculosis.tetanus, meningitis, and tuberculosis.
However, most bacteria are very useful:However, most bacteria are very useful: E. coliE. coli helps us digest our food. helps us digest our food. Many are important decomposers in our Many are important decomposers in our
ecosystem.ecosystem. RhizobiumRhizobium provides plants with nitrogen. provides plants with nitrogen. A few bacteria are used to clean up small oil A few bacteria are used to clean up small oil
spills in the ocean.spills in the ocean.
VaccinationsVaccinations A weakened form of the pathogen A weakened form of the pathogen
(virus/bacteria) is used to (virus/bacteria) is used to stimulate the production of stimulate the production of antibodies.antibodies.
However, bacteria and viruses However, bacteria and viruses have very high reproductive rates, have very high reproductive rates, which result in many mutations.which result in many mutations.
Thus, bacteria and viruses evolve Thus, bacteria and viruses evolve quickly, often requiring a different quickly, often requiring a different vaccine every year.vaccine every year.
http://www.biojobblog.com/vaccination(5).jpg
http://www.biojobblog.com/vaccination%5B1%5D.JPG
There are two types There are two types of vaccines of vaccines (immunities):(immunities):
Active – person is Active – person is injected with the injected with the actual pathogen, actual pathogen, and immune cells and immune cells make their own make their own antibodies against antibodies against the disease, the disease, immunity is immunity is permanentpermanent
Passive – person is Passive – person is injected with injected with antibodies that fight antibodies that fight the disease, but the disease, but immunity is immunity is temporarytemporary
http://www.iavi.org/viewpage.cfm?aid=1682