Chapter 18 Viruses and Bacteria

Chapter 18 Viruses and BacteriaPages 476 - 4951A Rhinovirus

2The Flu

4What is a Virus??Non-living particles that cant reproducenucleic acids (DNA or RNA) enclosed in a protein coat

Smaller than the smallest bacterium Do replicate on their ownMust have a host5VirusesDont carry out respiration, develop or grow~~Influenza, smallpox, HIV, Herpes I and Herpes IICan mutate to become more dangerousBacteriophages infect bacterial cellsAll living organisms can contract virusesSome are species specific HIV only affects humans Have to have a host to replicateFound soil, air water6Structure of Bacteriophage that Infects Bacteria

7Bacteriophage

8Bacteria Phages Amplified with Electron Microscope

9Virus Amplified by Electron Microscope

10Viruses Replicate (NOT real reproduce)11Viral Replication CyclesLytic CycleLysogenic Cycle12Lytic CycleA virus takes over a hosts genetic material The cell bursts (Lysis) and viruses spread Uses its structures and energy to replicate many viruses 13

Lytic Cycle14Lysogenic Cycle** The viruss nucleic acid (DNA/RNA) is integrated into the host cells chromosome

** The virus lay dormant as the cell reproduces itself ** The cell is then called a provirus15Lysogenic Cycle

After the virus has inserted its genetic material (Step 1)16

Replication ActivityCompared to a Factory18Types of Viruses19Tobacco Mosaic virus causes leaves to turn yellow and cant be sold at market

20Proviruses(Undergo the lysogenic cycle)Herpes Zoster (chicken pox), Herpes simplex I (cold Sores), herpes simplex II (Genital Herpes), and hepatitis B (affects liver)21RetrovirusRNA virusesRNA being their only HIV that causes the disease AIDS22Retrovirus HIVInfects white blood cells (remember B and T Cells!!!)Released into the blood stream by exocytosis and infect other white blood cells.23HIV

24Cancer and VirusesViruses linked to cancer disrupt mitosisHPV is the most commonHuman Papilloma Virus causes genital warts and accounts for about 76% of cervical cancers25Bacteria

26Bacteria - ProkaryotesArchaebacteria The extremist; Oldest; salt-loving; heat-lovingEubacteriaSome are photosynthetic - photosynthesis Some undergo chemosynthesis break down surrounding organic compounds for foodSome are heterotrophs eat their own food

27Bacteria ReproductionBinary FissionConjugation Type of ReproductionAsexualSexual-------------------------------------------------------------------------------------------- How it HappensOne bacterium one bacterium makes a copy oftransfersits chromosomeschromosomes toand splits into twoanother bacteriumthrough pili ----------------------------------------------------------------------------------------------- Description of CellsGeneticallyGenetically different Producedidentical28Bacteria

Flagellum RibosomeCytoplasmChromosomecapsuleCell WallCell MembranePili29Bacteria AdaptationsEndospore forms around bacteria during harsh conditionsCells grow and reproduce Can produce toxinsBotulism (food poisoning), anthrax (lives in soil)Can mutate quickly to environmental change and become more dangerous30HarmfulSome make you sick and can bcome antibiotic resistantStrep throat Food poisoning Some Pneumonias Lyme disease TuberculosisCavities31Helpful to HumansNitrogen fixation (plant root convert nitrogen gas into usable nitrogen for the plant)Return nutrients to soilProduce oxygenProduction of cheese, yogurt and picklesE. coli in the intestinesUsed in farming, medicine and food industry

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