Question

1. Like phospholipids, lipopolysaccharides have a hydrophilic head and a hydrophobic tail.
True or false

2. The outer membrane of Gram negative bacteria contains lipopolysaccharides

T or F

3. Biofilms and pure culture are formed by only one type of microorganism

T or F

4. Any given antibiotic will have the same minimum inhibitory concentration (MIC) against any test microorganism.

T or F

5. Production of antibiotics by the microorganism is not affected by the culture conditions

T or F

6. What bacterial structure has a role in the spreading of antibiotic resistant genes?

Flagellum , pilus, cellular membrane or peptidoglycan

7. Select the best answer. The outer membrane is composed by...

a.Phospholipids and proteins, b.Lipopolysaccharide, c. (Lipopolysaccharide, phospholipids, and proteins),d.Lipopolysaccharide and phospholipids

8. DNA is shared between microorganisms by lateral gene flow. In this process only DNA fragments encoding important bacterial functions are shared.

T or F

9. Select the correct statement about the biological activity of Lysozyme

a. Inhibits the synthesis of the peptidoglycan b.Destroys the peptidoglycan c.

Inhibits the synthesis of the outer membrane d. Inhibits the synthesis of cell membrane

10. Pure cultures are advantageous as a method to study microbial physiology because...

a. The majority of the prokaryotes of the earth biome can be culture as pure cultures b.The interaction between the different microorganism present in the biofilm are preserved in pure cultures c.All of the above are correct d.

All of the above are incorrect

11.Lateral gene flow is an important mechanism implicated in the spreading of antibiotic resistance mechanisms

T or F

12. Lipopolysaccharadies are located in the inner leaflet of the outer membrane

T or F

13. Select the mechanism of lateral gene flow in which the DNA is released from one cell in to the environment and then is taken from there by another cell

a. Transformation b. Transduction c. Conjugation d. Transfection

14. Antibodies against -------- could prevent the attachment of microorganisms to biological surfaces.

a. Flagellum b. Pilus c.cellular membrane d. peptidoglycon

15. The transport of hydrophilic substances across the cellular membrane is mediated by proteins

T or F

16. Proteins forming pores in the cellular membranes are implicated in....

a. Transport of hydrophobic substances b. Transport of hydrophilic substances c. Cellular motility d. Adhesion of bacteria to host surfaces

17. Mutations altering the pili could change the pathogenic characteristics of the bacteria
T or F

18. Microorganism grows in the laboratory forming

a. biofilms, b. pure cultures, c. monolayers, d. bacterial communities

19. The cross-streak method is commonly use in the search for...

a. antibiotic-producing microorganisms, b.To characterize the sensitivity of particular microorganisms to newly identify antibiotics, c. All the statements above are correct d. All the statements above are incorrect

20. Amino acids located in the internal surface of the channel of a channel-forming protein inserted in a biological membrane are:

a. A mixture of hydrophilic and hydrophobic, b. hydrophilic, c. hydrophobic, d. it is unpredictable

21. Broad-spectrum antibiotics are always safer than narrow-spectrum antibiotics in clinical infections.
T or F

22. Antibiotics are produced as a group of closely related compounds and therefore purification of the active form is challenging.

T or F

23. Which of the following antibiotics you expect to encounter a higher frequency of resistant microorganisms in our community?
a. Antibiotic A that has been used for 3 years in El Paso, b. Antibiotic B that has been used for 15 years in El Paso c. Antibiotic C that was introduced last month in El Paso d. The frequency of resistant microrganism will be very similar for all of these antibiotics.

24. Polymyxin B is an antibiotic that binds to lipopolysaccharide. Classify the spectrum of this antibiotic...

a. broad, b. narrow, c. general, d. particular

25. The cell membrane in Gram negative bacteria is rich in lipopolysaccharide.

T or F

26. Select the mechanism of lateral gene flow in which the DNA is transferred by cell-to-cell contact through pili to another cell...

a. transfection, b. conjugation, c. transduction, d. transformation

27. Always hydrophilic substances enter the cell by diffusion across the cell.

T or F

28. Antiviral drugs are difficult to develop because

a.The market for antivirals is very small, b. Viral infections do not have a major impact in human health, c. A relevant selective toxicity is difficult to achieve in antiviral drugs, d. All the statements above are correct.

29. Polymyxin B is an antibiotic that binds to lipopolysaccharide and destroy the integrity of the outer membrane. What function of the outer membrane you predict will be primarily affected by polymyxin B?

a. Maintenance of the shape and rigidity of the bacteria, b. Bacterial motility, c.

Semi-permeability barrier, d. Adhesion to other microorganisms

30. Pure cultures are useful to determine antibiotic susceptibility in clinical infections.

T or F

31. Phospholipids are located in the inner leaflet of the outer membrane

T or F

32. Polymyxin B is an antibiotic that binds to lipopolysaccharide. Will the bacterial peptidoglycan limit the accessibility of polymyxin B to the lipopolysaccharide?

a. No, b. Yes, c. Yes, but only in Gram negative bacteria. d. Yes, but only in Gram positive bacteria.

33. The Gram staining is largely influence by the thickness of the...

a. pilus, b. cellular membrane, c. peptidoglycan, d. flagellum

34. Lateral gene flow is an important mechanism of evolution.

T or F

35. Lateral gene flow has low importance in the spreading of genes implicated in bacterial pathogenesis (ability of bacteria to cause diseases).

T or F

******36. What would be your prediction?

a. Bacteria are more sensitive to penicillin during the stationary phase of growth, b. Bacteria are more sensitive to penicillin during the log phase of growth, c. The sensitivity to penicillin is very similar during all the phases of the growth curve., d. .....(.missing option)

37. Amino acids located in the external surface of a channel-forming protein inserted in a biological membrane are:

a. A mixture of hydrophilic and hydrophobic, b. hydrophilic, c. hydrophobic, d. it is unpredictable

38. Lateral gene flow is implicated in the adaptation of the bacteria to the environment.

T or F.

Answer 1

1. True.

2. True.

3. False

4. False

5. False

6. Pilus

7. d. lipopolysaccharides, and phospholipids

8. False

9. b. destroys the peptidoglycan

10. a. The majority of the prokaryotes of the earth biome can be culture as pure cultures

11. True

12. False

13. a. Transformation

14. Peptidoglycan

15. True

16. b. transport of hydrophilic substances

17. True

18. b. pure cultures

19. a. antibiotic producing microorganisms.

20. b. hydrophilic