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Presentation on theme: "Microbiology."— Presentation transcript:

1 Microbiology

2 Bacteria 1. How many cells? 2. Type of organism? 3. Nucleus?
4. Membrane bound organelles? 5. What kingdom are they in? Unicellular No Prokaryotic No Monera

3 What does bacteria look like?
Coccus (sphere) Bacillus (rod) Spirillum (spiral)

4 How do bacteria get their energy?
Autotrophic Photosynthesis (use suns energy) Chemosynthesis (use chemical energy)

5 Heterotrophic Saprophytic: obtain food from dead organisms Parasites: live off of living organism; damage that organism Mutualism: Bacteria and living organism benefit (Ex: E. coli- intestinal bacteria)

6 Respiration Aerobic: Live in presence of oxygen
Anaerobic: Live in absence of oxygen

7 Movement Flagella: Acts like a motor to propel bacteria forward
Slime layer: Secrete slime and “slide” along the slime (similar to a slug)

8 Reproduction Binary fission: asexual; divide in two
Conjugation: share DNA between two bacterium Endospores: Survive in extreme conditions (temp, drought, flood, radiation)

9 Bacteria are helpful Nitrogen fixation, food preparation, decay Bacteria are harmful Disease, spoiled food

10 Nitrogen Fixation Symbiotic (mutualism) relationship between bacteria and plants. Bacteria get food from plants, plants get nitrates from bacteria

11 Food Preparation Bacteria are used in the production of many foods such as buttermilk, cheese, yogurt, vinegar, and sauerkraut.

12 Decay: some bacteria are decomposers
Breakdown dead organisms sewage, waste in landfills (help recycle materials back into soil)

13 Other Benefits Antibiotic production
E. coli in human intestines (make vitamin K, essential amino acids, digestion of some sugars) Genetic engineering Cellulose digestion (symbiotic relationship with grazers)

14 Disease Most infections are caused by bacteria
Gangrene, tuberculosis, leprosy, strep throat, pneumonia, syphilis, typhus

15 Spoiled Food Food poisoning is caused by bacteria Botulism Salmonella

16 Viruses

17 Structure Protein coat surrounds a nucleic acid core (DNA or RNA)
# of genes: few to over a hundred

18 Reproduction Must have a host cell Cannot reproduce on its own
Two ways to reproduce Lytic cycle Lysogenic Cycle

19 Lytic Cycle Attachment of virus to host cell Inject DNA into host cell
Replicate DNA Assemble new virus particles Lyse (kills host cell)

20 Lysogenic Cycle Attachment of virus to host cell
Inject DNA into host cell Viral DNA becomes part of host cell (prophage) Dormant, host cell reproduces Activation and lyse


22 Diseases caused by Viruses
HIV Influenza (flu) Common Cold

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