Micro.Review.Part2

Micro.Review.Part2 - MCB 5252 Exam FOUR Review Questions;...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MCB 5252 Exam FOUR Review Questions; Part TWO 1. What are the classes of antibiotics that target protein synthesis mechanism act on bacterial ribosomes a. Am inoglycoside (bacteriacidal) b. s (bacteriastatic??) c. (bacteriastatic) 2. Why protein synthesis process is an appropriate site for antibacterial agents and not for others? a. Although protein synthesis proceeds in essentially the same way in prokaryotes and eukaryotes, some differences can be exploited to achieve selective toxicity. b. The ribosomal units involved in m RNA t ranslation in bacterial systems are smaller (30S & 50S) than in eukaryotes (40S & 60S) 3. What are the three basic principles of antim icrobial therapy? 1. Selective toxicity - to exploit differences in structure and metabolism of pathogens and host cells (to kill organisms, not man!) 2. Reach the site of infection at inhibitory concentrations 3. Penetrate and bind to target, avoiding inactivation and extrusion 4. How resistance may disseminate throughout the m icrobial world? a. Chromosomally-mediated resistance: mutant selection b. Plasm id-mediated resistance: spread of resistance plasmid c. Plasm id-mediated resistance on a t ransposon: spread of resistance gene d. Other mechanisms of resistance: i. Altered target- target enzyme/other sites altered ii. Altered uptake- increase impermeability of cell wall (loss of porins) or pumping drug out (efflux) iii. Drug inactivation- production of enzymes which modify/destroy antimicrobials 5. Name the typical target of antibiotics a. Cell wall synthesis (mammalian cells lack a cell wall) b. Protein synthesis (ribosome) c. Nucleic acid synthesis i. Microbial folate synthesis ii. Inhibitors of DNA replication d. Cell membrane function 6. What is the mechanism of action of beta lactam antibiotics? a. include the penicillins, cephalosporins, carbapenems (e.g. imipenem), monobactams (aztreonam), and cephamycins b. bind to penicillin binding proteins (PBPs) inhibit this enzyme from catalyzing the link between L-lysine and D-alanine **different bacteria may have different PBPs 7. Which organisms make antibiotics and what is its purpose in nature? a. Fungi (molds) b. Bacteria c. Penicillium, Streptomycin (a bacteria), and Cephalosporium **both produce antibiotics to destroy competition 8. Name possible ways bacteria may acquire resistance to antibiotics See #4a-c 9. Name possible ways bacteria make antibiotics ineffective See # 4d 10. Name drugs targeting: cell membrane, DNA, RNA a. Cell wall: beta-lactams (penicillin), glycopetptides (vancomycin), bacitracin, cycloserine b. DNA: inhibit ion of DNA replication like quinolones (ciprofoloxacin), metronidazole (oxidizes DNA causing strand breaks) c. RNA: am inoglycoside ( inhibit protein synthesis in bacteria), rifamycins (blocks m RNA inhibits RNA polymerase) 11. What is meant by selective toxicity?...
View Full Document

Page1 / 11

Micro.Review.Part2 - MCB 5252 Exam FOUR Review Questions;...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online