1. Chapter 19 Bacteria & Viruses 19.1 Prokaryotes

2.  Single-celled  Lack nucleus  Smallest, most common microorganism

3. Classification

4.  Eubacteria (D/Bacteria)  Larger kingdom; greater diversity  Cell wall w/peptidoglycan (carbo) E. Coli bacteria  Shapes

5.  Archaebacteria (D/Archaea)  Extremist (anaerobic methanogens)  Cell wall w/out peptidoglycan  DNA sequence of key genes = eukaryotes Bacteria in hot springs Billion yr old cyanobacteria

6. Identification  Shapes  Bacilli: rod-shaped  Cocci: spherical  Streptococcus: chains  Staphylococcus: clusters  Spirilla: spiral-shaped Streptococcus Staphylococcus

7.  Cell Walls  Gram + : single layer; stain purple  Gram - : double layer; stain pink (disease)

8.  Movement  Flagella: whip-like structure

9.  Energy  Autotrophs (make food)  Photoautotrophs: cyanobacteria (aerobic)  Chemoautotrophs: anaerobic  Heterotrophs (obtain food) Cyanobacteria

10.  Respiration  Obligate aerobes: respire/need O 2  Obligate anaerobes: ferment/killed w/ O 2  (C. botulinum)  Facultative anaerobes: resp/ferm C. botulinum produces the potent nerve toxin that causes botulism. Flesh eating bacteria Tetanus

11.  Reproduction  20 min doubling time  Binary Fission: Asexual reproduction  DNA replicated & divides  Identical daughter cells

12.  Conjugation: Sexual reproduction  Genetic material exchange  Protein bridge forms between bacteria (pilli)

13.  Endospore  Internal wall enclosing DNA/cytoplasm  Remains dormant (months to centuries)

14. 19.2 Bacteria in Nature  Decomposers  Recycle nutrients  Sewage treatment

15.  Nitrogen Fixation  Fixing N2 (air) to NH3 (ammonia=fertilizr)  Plants need N for AA to make proteins

16.  Disease  Pathogens  Tissue damage: tuberculosis (lungs) Table 19.6 Tissue specificity as a factor in infectious disease Disease Tissue infectedOrganism DiphtheriaThroat epithelium Corynebacterium diphtheriae GonorrheaUrogenital epitheliumNeisseria gonorrhoeae Cholera Small intestine epithelium Vibrio cholerae PyelonephritisKidney medullaProteus sp. Dental cariesOral epithelium Streptococcus mutans, S. sobrinus, S. sanguis, S. mitis Spontaneous abortion (cattle) PlacentaBrucella abortus Acquired immunodeficiency syndrome (AIDS) T helper lymphocytes Human immunodeficiency virus (HIV) MalariaBlood (erythrocytes)Plasmodium sp.

17.  Toxins: salmonella, tetanus, botulism Tetanus: permanent contraction (death by respiratory failure) Botulism: no contraction (death by respiratory failure)

18.  Vaccines: stimulate immune system  Antibiotics: block growth/reproduction

19.  Human Uses  Food; Industrial; Genetic engineering Bacteria products for biological filters BLOCKING OUT GAS. Unlike the left tower, which uses chemicals, the tower on the right at this wastewater-treatment plant now uses bacteria-covered foam blocks (inset) to eliminate the hydrogen sulfide bubbling from treated sewage. BLOCKING OUT GAS.This wastewater-treatment tower bacteria-covered foam blocks (inset) to eliminate the hydrogen sulfide bubbling from treated sewage. Solid waste digester takes solid organic waste and uses bacteria to turn it into methane, which is then used to generate electricity. Daniel Bond, from the University of Massachusetts, Amherst, helped create a battery that uses common bacteria to turn organic matter from the ocean floor nto electricity. In May he will move his laboratory to the University of Minnesota, where he will work with other faculty on renewable energy.

20.  Controlling  Sterilization: Heat; Disinfectant  Food: Refrigerate, heat, seal, preserve

21. 19.3 Viruses

22.  What is it?  Non-living; lack cells; need host to reproduce  Smaller/simpler than smallest cells  DNA/RNA core; protein coat (capsid)

23.  Infection  Species specific (bacteriophage = only bacteria)

24.  Lytic: host cell destroyed  Virus enters host (DNA/RNA injected)  Replicates using materials of host DNA  Host burst and releases many new virus Lytic Viral Reproduction Phase

25.  Lysogenic: uses host indefinitely  Virus embeds DNA (prophage) into host DNA  Replicated w/ host DNA  Will eventually becomes lytic Lysogenic Phase

26.  Disease  Vaccines: must receive before infection  Cancer: oncogenic virus  Disrupt cell growth/division

27.  Retrovirus: contain RNA  DNA copy made and inserts into host DNA  RNA to DNA (backwards)  AIDS