1. Bacteria

2. Prokaryote – single celled with no nucleus Eubacteria – peptidoglycan (a carbohydrate) cell wall Archaebacteria – cell wall of lipids, no peptidoglycan in the cell wall

3. Identifying Prokaryotes Shape a. bacilli – rod shaped b. cocci – spherical shaped c. spirilla – corkscrew shape http://biology.clc.uc.edu/graphics/bio106/bacteria.jpg

4. Identifying Prokaryotes Cell Wall – use gram stain i. gram positive has peptidoglycan wall ii. gram negative has no peptidoglycan wall Movement – may or may not move >flagella >lash, snake, or spiral forward >glide on slime like secreted layer

5. Metabolic Diversity Heterotrophs: chemotrophs & photoheterotrophs Autotrophs >photoautotrophs – ex. Cyanobacteria http://steel.ced.berkeley.edu/cris/ hiddenecologies/HE/wp-content/uploads/ 2006

6. Metabolic Diversity >chemoautotrophs – energy from chemical reactions is used to make food (from ammonia, hydrogen sulfide (H 2 S), nitrites, sulfur, or iron)

7. Growth & Reproduction Binary fission http://www.biology-resources.com/drawing-amoeba-reproduction.html

8. Growth & Reproduction Conjugation http://americanscientist.org/Libraries/images/thumbnail/20033711443_307.gif

9. Growth & Reproduction Spore Formation: structures of DNA & some cytoplasm (formed when conditions were unfavorable for growth) remain dormant for months or years until the right conditions exist http://ppdl.purdue.edu/PPDL/images/ daylily_rust_spores400x.jpeg

10. Importance of Bacteria Decomposers – recycle nutrients & maintain equilibrium Nitrogen fixers – change nitrogen gas into useable compound plants can use www.windows.ucar.edu/earth/climate/images/ nitrogencycle.jpg

11. Importance of Bacteria Human use – make food & beverages, clean up oil spills, remove waste products from ground, synthesize drugs & chemicals, make vitamins our bodies need (E.coli in large intestine) www.javno.com/slike/slike_3/r1/g2007/ www.fotosearch.com/LIF145/pdb07006/ http://library.thinkquest.org/J002755/graphics/vitamins.gif www.javno.com/slike/slike_3/r1/g2007/www.fotosearch.com/LIF145/pdb07006/http://library.thinkquest.org/J002755/graphics/vitamins.gif

12. Viruses Virus: particles of nucleic acid, protein, & sometimes lipids (typically DNA or RNA core with a protein coat) >only reproduce by infecting living cells >use living cells to make more viruses Image by Karsten Schneider/Science Photo Library

13. Viruses Capsid: protein coat of a virus >capsids bind to cell host & “trick” the cellto let the virus inside the healthy cell Bacteriophages: viruses that only infect bacteria

14. Viral Infection Lytic – virus enters a cell, makes copies of itself, & causes the cell to burst Lysogenic - virus combines its DNA with the host cell and the viral DNA replicates with the host’s DNA

15. Viral Infection

16. Retroviruses Viruses that contain RNA Named retro because they copy genetic information from RNA to DNA (usually genetic information is copied from DNA to RNA

17. Retroviruses

18. HIV VIRUS www.chm.bris.ac.uk/.../levasseur/images/hiv.GIF

19. The “take-home” message STAY HEALTHY WASH YOUR HANDS, ETC.