Biology152 Unit 2 Paramedical Microbiology

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Biology 152:

Paramedical Microbiology Study Guide:

UNIT 2

Reading: Tortora

Chapters 3, 4, pp. 367-374 Items in Red and Bold: may not be covered in class, so you will need to look up this information in the text (Tortora) Define the following terms: bacteriophage taxis axial filament chemotaxis fimbriae phototaxis pili plasmid Answer the following questions:

1. Compare and contrast the following different types of microscopy, and give an example of how each would be used:

a. compound light (brightfield) microscope b. phase contrast microscopy c. fluorescence microscopy d. transmission electron microscopy e. scanning electron microscopy.

2. If you are looking at an organism that is 40 μm in length, what is its length in millimeters?

3. Organize the following in order by size (largest to smallest), and estimate a metric size range for each of them. Describe what type of microscope would be used to view each of them.

 a. b. c. d. e.

protein

molecule mosquito

 bluebird

white blood cell

Staphylococcus epidermidis (bacterial cell)

 4. Identify the three basic shapes of bacteria. What specific arrangements of cocci and bacilli are found? (streptococci, etc)

5. Describe the basic structure and components of a prokaryotic cell including the cell wall, membrane, nucleoid, ribosomes, inclusions, and endospores.

6. How do the cell walls of Mycoplasma, the Archaea and Mycobacterium differ from the cell walls of most other bacteria?

7. Describe the structure and function of the plasma membrane in prokaryotic cells.

8. Review the structure and function of the components of a typical eukaryotic cell. Be able to differentiate between plant and animal cells (this was covered in Bio 130 and should be a review).

9. Describe the function and structure of each of the following components of viruses: nucleic acid, capsid, capsomeres, envelope, spikes.

10. Describe the four basic types of virus morphology.

11. Describe the structure of peptidoglycan. What is the major advantage conferred by a bacterial cell wall made of peptidoglycan? What is the mechanism of action of penicillin?

12. Compare and contrast the composition and characteristics of the cell wall of gram negative and gram positive cells.

13. What type of toxin is LPS, and how does it contribute to the pathogenicity of Gram negative bacteria?

14. Compare and contrast Gram positive and Gram negative bacterial cell walls in terms of their sensitivity to desiccation (drying out), physical disruption, lysozyme, and penicillin.

 15. Describe the steps of the gram stain, and know why gram + and gram - cells stain differently.

16. Compare and contrast prokaryotic cells, eukaryotic cells, and viruses with regards to size, complexity, general structure, where genetic material is located, and whether or not they are acellular, unicellular, or multicellular.

17. Explain why bacteria cannot be identified based on morphology alone.

 18. Compare and contrast the two forms of glycocalyx. Where is the glycocalyx found in the cell? What type of molecule is the glycocalyx made of? What are the advantages of having a glycocalyx?

 19. Describe the basic structure and function of bacterial flagella, and be able to identify common flagellar arrangements. Explain how bacteria use run and tumble locomotion to move in their environment (chemotaxis).

20. What is the survival advantage of forming endospores? What triggers endospore formation? Name 2 genera of bacteria that commonly form endospores. Contrast between the terms endospore and vegetative cell.