1. “Prokaryotes” - single-celled organisms that do not have membrane-bound organelles

2. Bacteria versus Archaea BacteriaBothArchaea -live everywhere -can cause diseases -cell wall contains peptidoglycan -small (1-10  M) -prokaryotic -single celled -DNA as a single circular chromosome -no membrane-bound organelles -both reproduce asexually via binary fission -Both extremophiles & mesophiles (moderate T) -do not cause diseases -cell wall does not contain peptidoglycan

3. Archaea are rather difficult to study… –Won’t grow in a Petri dish…

4. Live in volcanic hot springs…

5. And acid mine drainage…

6. Archaea Differ from bacteria in their biochemistry and metabolism –Phospholipid composition (ether-linked lipids) –Cell wall composition (some contain pseudomurein) –Metabolism: use a wide variety of food sources (autotrophic or heterotrophic)

7. Bacteria Classified by Shape: 1.spherical: coccus or cocci, ex. strep throat

9. 2. rod-shaped: bacillus or bacilli, ex. E. coli

10. 3. spiral: spirillium or spirilla, ex. Treponema pallidium, the cause of syphilis

11. Classified by Respiration: 1)obligate aerobes: must have oxygen ex. Mycobacterium tuberculosis

12. 2) obligate anaerobes – can only grow in the absence of oxygen ex. deep soil bacteria, deep marine bacteria, Treponema pallidium

13. 3) facultative anaerobes – can live in both oxygen – rich and oxygen – deprived conditions, ex. E. coli

14. under anaerobic conditions (no oxygen) bacteria will undergo anaerobic respiration, producing ethanol or lactic acid and energy

15. Classified by Nutrition 1)heterotrophic - most bacteria, obtain nutrients from other organisms i) parasitic: detrimental to host ii) saprophytic: decompose dead organic matter iii) symbiotic: contribute to host’s well- being

16. 2. autotrophic -produce own food i)photosynthetic: produce sugars using light energy ii)chemosynthetic: produce sugars using chemical reactions

17. General Structure of a Bacterium cilia

18. Bacterial Reproduction there are two types of bacterial reproduction 1)Binary Fission - creates two identical daugther cells - asexual

19. 2) Conjugation -exchange of genetic information between two bacterial cells -involves the copy and donation of a circular plasmid through a pilus -sexual -cause of large-scale antibiotic resistance! plasmid pilus bacterial chromosome

21. A sneaky alternative: endospores during times of unfavourable environmental conditions some bacteria can form highly resistant endospores - dormant forms where the genetic material is protected by a thick wall - once bad times pass the bacteria will re- emerge, ready for binary fission

22. Being Homo sapiens centered, we tend to define bacteria as helpful or harmful to us…

23. Helpful Bacteria 1)Bacteria in medicine: - can make things for us: ex. engineered bacteria make human growth hormone and insulin 2) Bacteria in industry: - make bioplastics: fully degradable plastics (take 6 months as opposed to 400 years to degrade!)

24. 3) Bacteria as decomposers - can be used in bioremediation to clean up oil spills, clear our waste water, etc. by converting harmful substances to less harmful ones

25. 4) Bacteria as food makers ex.1 Cheese– originally it was the action of bacteria producing acid that caused the separation of a curd from the milk ex. 2 Chocolate – without bacteria we would not have chocolate!!!

26. 5) Bacteria in and on our bodies

27. Harmful Bacteria 1) Harmful to the industry - bacteria can cause degradation of desired products ex. Pasteur was originally hired by a wine maker to figure out why what should be wine was coming out as vinegar…

28. 2) harmful to our health - there are many many many pathogenic (disease-causing) bacteria and we suffer losses from them every year

29. humans vs. microbes: Antibiotic Resistance the overuse of antibiotics over the last decades has lead to a rise in antibiotic resistant bacteria, i.e. bacteria that do not react to antibiotics done by selecting and then unintentionally breeding resistant bacteria

30. we perform a similar experiment in our bodies when we do not follow instructions for our antibiotics 1) low doses and not enough exposure selects bacteria that are resistant 2) given time the resistant bacteria take over

31. How do hand sanitizers work? the alcohol in the sanitizer causes lysis of bacterial cells (and yours also, btw)

32. Penicillin Inhibits Staphylococcus aureus Note that growth of the bacteria Staphylococcus aureus is inhibited in the area surrounding the invading penicillin- secreting Penicillium mold colony.