viruses - Viruses & Bacteria Chapter 17 Biology 11...

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Unformatted text preview: Viruses & Bacteria Chapter 17 Biology 11 Presentation put together by Mandie Lynn Walls What are Viruses A virus is a non­cellular particle made up of genetic material and protein that can invade living cells. T4 Bacteriophage Herpes Virus Herpes Escherichia Coli Bacterium E. coli is a bacterium. That is a crude cell, it is not a virus because viruses are protein containers with DNA cores or RNA cores. E. Coli and the E. Coli and the Bacteriophage What it looks like in real life T h e S truc ture O f a Virus Viruses are composed of a core of nucleic acid The Nucleic acid core is surrounded by a protein coat called a capsid The Nucleic core is either made up of DNA or RNA but never both C y c le o f Ly tic a nd Ly s o g e nic Vaccines Vaccines ► Viruses grown on chicken embryos are attenuated vaccines ► Another type of vaccine is made by heat killing the virus R e tro virus C h a ng e DNA into R NA. Exa m p le o f a R e tro virus is HIV A typical, "minimal" retrovirus consists of: •an outer envelope which was derived from the plasma membrane of its host •many copies of an envelope protein embedded in the lipid bilayer of its envelope •a capsid; a protein shell containing •two molecules of RNA and •molecules of the enzyme reverse transcriptase Bacteria Cell Prokaryotes Cells that do not have a nucleus Exist almost every where on earth Grow in numbers so great you can see them with the unaided eye Are placed in either the Eubacteria or the Archebacteria Kingdoms Make up the smaller of the two kingdoms Eubacteria Eubacteria Make up the larger of Make the two prokaryote kingdoms kingdoms Generally are Generally surrounded by a cell wall composed of complex carbohydrates carbohydrates Photosynthetic bacterium Bluish­greenish color Contain membranes that carry out the process of photosynthesis Do not contain the same type of chloroplasts as plants do This bluish­greenish algae can be found nearly everywhere on earth. Can survive in extremely hot environments and even extremely cold environment Cyanobacteria Cyanobacteria Archaebacteria Archaebacteria Lack important Lack carbohydrate found in cell walls in Have different lipids Have in their cell membrane membrane Different types of Different ribosomes ribosomes Very different gene Very sequences sequences Archaebacteria can Archaebacteria live in extremely harsh environments harsh They do not require They oxygen and can live in extremely salty environments as well as extremely hot environments. environments. Identifying Prokaryotes Identifying Prokaryotes Cell Shape Cell Wall Movement Bacterium Shapes Cocci~ Sphere shaped bacteria Bacillus~ Rod shaped bacteria Spirrillium ~ Spiral shaped bacteria Flagella~ Leg-like structures that help to propel the bacterium. Gram + and Gram – Bacterium Cell Walls Cellular Walls Cellular Walls Chemical nature of a cell wall can be determined by Gram Staining By finding out what color the cell produces when it is gram stained you can figure out the type of carbohydrates in the cell wall Movement • Flagella ~ Tail like structure the whips around to propel the bacterium • Cillia ~ Miniature flagella surround the cell that help to “swim” • Non motile ~ Sticky cillia like structures that keep the bacterium from moving Flagella Bacteria and their energy Bacteria Autotrophs Chemotrophs Heterotrophs Autotrophs Make their own energy Using Solar energy Eg. Cyanobacteria Chemotrophs Chemotrophs Make own Energy Using Chemical energy Eg. Archaebacteria Heterotrophs Obtain food By eating Eg. E­coli Bacteria Respiration Bacteria Respiration Obligate Anaerobes Facultative Anaerobes Obligate Aerobes Live without Oxygen Can live with or without oxygen Cannot live without oxygen. Bacteria Reproduction Bacteria Reproduction Binary Fission Conjugation Spore Formation Cellular organism copies it’s genetic information then splits into two identical daughter cells Conjugation A type of Bacteria Sex Two organism swap genetic information, that contains the information such as a resistance to penicillin Spore Formation: Endospore Spore A type of dormant cell Exhibit no signs of life Highly resistant to environmental stresses such as: ­High temperatures ­Irradiation ­Strong acids ­Disinfectants Endospores are formed by vegetative cells in response to environmental signals that indicate a limiting factor for vegetative growth, such as exhaustion of an essential nutrient. Symbiosis Symbiosis Close relationship between to species in which at least one species benefits from the other Live together for LIFE Parasitism Bacteria exploit the host cell, injuring them Eg. Mychobacterium tuberculosis Mutualism Symbiosis in which two of the species live together in such a way that both benefit from the relationship Eg. E-coli Nitrogen Fixations Process by which nitrogen in the atmosphere is converted into a form that can be used by living things THE END This powerpoint was kindly donated to is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching. ...
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This note was uploaded on 11/07/2011 for the course BIOLOGY 100 taught by Professor Staff during the Winter '08 term at BYU.

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