Question

1. Explain the difference between a bactericidal drug and a bacteriostatic drug.Which one would be a better antibiotic for patients and why?
2. Describe the similarities and differences in the drugs penicillin and vancomycin. In your answer describe the targets and mechanisms of action for each. Which would you prescribe to a patient with S. aureus infection and why?
3. Describe the difference between prokaryotic ribosomes and eukaryotic ribosomes. How does this difference allow us to safely target prokaryotic ribosomes?
4. Explain the mechanism of action for the aminoglycoside drugs. What is their target and how does this kill bacterial cells?
5. Explain the mechanism of action for the quinolone drugs. What is their target and how does this kill bacterial cells?
6. What is the SOS response system in E. coli?   What is the role of the Rec A and LexA proteins in the SOS response system?   What role does the SOS response system play in quinolone treated bacterial cells?

Answer 1

1. Bactericidal drug are the one which kill the bacteria whereas the bacteriostatic drug are the one which inhibit the growth of the bacteria. The better antibiotic for the patient is bactericidal drug because it kill the bacteria permanently.

2. Similarity between the vancomycin and penicillin

Both the antibiotics target the cell wall synthesis components of the bacteria.

Difference between the vancomycin and penicillin

Penicillin is mainly used for gram negative bacteria and vancomycin is used for gram positive bacteria. Vancomycin is given to the patient that have allergy to the peniciilin drug.

I would describe vancomycin because it is a bactericidal antibiotic that kill the bacteria.

3. Prokaryotes have 70S ribosome whereas eularyotes have 80S ribsome. The 70S ribosome unit is made up of two subunit 30S and 50S where eukaryotic 80S ribosome are made up of two subunits which are 40S and 60S. These differences help scientist to target prokaryotic ribosomal only.

4. Aminoglycoside drug like gentamycin are used against gram negative bacteria . These drugs inhibit the protein synthesis in bacteria and inhibit the growth of bacteria. This antibiotic bind to the 30S unit of ribosome and inhibit protein synthesis.

5. Quinolone drugs are more often to treat urinary and respiratory infection. It is a broad spectrum antibiotics that are effective against both gram positive and gram negative bacteria. This antibiotic inhibit the DNA replication in bacteria by inhibiting the activity of DNA gyrase and DNA topoisomerase.