MIC 541-Exam 4- Antimicrobials IV-1

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MIC 541-Exam 4- Antimicrobials IV-1
2013-04-14 14:21:14
MIC 541 Exam Antimicrobials IV

MIC 541-Exam 4- Antimicrobials IV-1
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  1. Cephems is a collective word for a group of antibiotics containing:
    Cephalosporins and Cefemycins
  2. Does Gram + have a periplasmic space?
  3. Do Gram - have a periplastic space?
  4. Do Gram - or Gram + have a periplastic space?
    Gram -
  5. Describe the general composition of Peptidoglycan:
    • n-acetyl glucosamine and n-muramic acid linked together
    • amino acid chain extends from n-muramic acid
    • The fourth amino acid (D-alanine) is linked to the 3rd Amino acid on the subsequent strand (DAP)
  6. terminal step of cell wall synthsis which is th target of penicillin:
    • cleaving of D-alaninin-D-alanine bond
    • D-alanine cross links with DAP
  7. After the D-alanine-D-alanine bond is cleaved in Peptidoglycan synthesis, how many amino acids are remaining?
  8. Peptidoglycan is in out outside the plasma membrane?
  9. Penicillin and cephalosporins attack what?
    The cross linking of the peptidoglycan
  10. Penicillins and cephalosporins attack what step (in terms of synthesis order)?
  11. What are the three very general steps in creating Peptidoglycan?
    • 1.) Synthesis of the individual component molecules
    • 2.) Transport of these molecules out of the cell
    • 3.) Assembly of these molecules into peptidoglycan
  12. Terminal step of cell wall synthesis is attacked by Penicillina nd cephalosporins
  13. Why are B-lactams important?
    • Most heavily perscribed antibiotic
    • b/c they are the most safe and efficaious antibiotics
  14. How were B-lactams named?
    After the B-lactam ring that they all contain
  15. What bond is the basis for efficacy in B-lactams?
    B-lactam bond (found between the N and C=0 in the B-lactam ring)
  16. Describe the B-lactam ring?
    • 3 carbons
    • 1 Nitrogen
  17. What defense do some bacteria have against B-lactams?
  18. What is the target of B-lactamases?
    B-lactam ring
  19. In what way, as discussed in class, were chemist able to protect teh B-lactam bond against B-lactamases?
    Creat a substituent that wraps around and inhibits attack
  20. What portion of a B-lactam antibiotic is available for chemical manipulation?
    The substituent arm extending from the B-lacatam ring on the opposite side as the thiazolidine ring
  21. What does PBP stand for?
    Penicillin binding protein
  22. What is a Penicillin binding protein?
    An enzyme that cross links and modifies peptidoglycan
  23. What enzymes ar responsible for binding D-alanine-D-alanine and creating crosslinking between strands of Peptidoglycan?
    • Penicillin binding proteins (PBPS)
    • B-lactam antibiotics are analogs of what?
    • D-alanine-D-alanine
  24. How do B-lactams inactivate PBPs?
    Binding to PBPs in place of D-alanine-D-alanine
  25. What is the significance of multiple PBPs, in terms of antibiotics?
    multiple pathways to attack PBPs = multiple pathways to kill bacteria
  26. Where are PBPs located?
    in the cytoplasmic membrane
  27. What is general action of B-lactams?
    They inhibit cell wall synthesis
  28. How many essential PBPs have been identified in E. coli?
  29. Drugs that attack PBP1 cause:
  30. The inhibition of which E. coli PBP causes lysis ?
  31. Antibiotics that effect PBP3 cause what?
  32. The inhibition of which E. coli PBP causes Filementation?
  33. Antibiotics that effect PBP2 cause:
    Change to oval shape
  34. The inhibition of which E.coli PBP causes the shape to change to oval?
  35. Why is PBP2 a good target?
    Because there are only a few molecules of PBP2 in the cell
  36. When were penicillins discovered?
  37. Who discovered Penicillins?
    Alexander Fleming
  38. What bacteria was inhibited in the discovery of Penicillin?
    Staph aureus
  39. What date (approx.) was Penicillin developed into a drug?
  40. Who developed Penicillin into a drug?
    Howard Florey
  41. Semisythetic antibiotics were first made when?
  42. Penicillin is the best choice antibiotic under what conditions?
    • The patient ins not allergic
    • the pathogen is susceptible
  43. You should always consider what antibiotic first?
  44. What are the only two reasons to not use Penicillins?
    • The pathogen is resistant
    • The patient is allergic