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. protein molecule

b. mosquito

c. bluebird

d. white blood cell

e.

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