11. Controlling Microbial Growth

PABA is __________ .

a. A substrate used in the production of penicillin

b. A type of β-lactamase

c. Molecularly similar to cephalosporins

d. Used to synthesize folic acid

Which of the following statements is false concerning antiviral drugs?

a. Macrolide drugs block attachment sites on the host cell wall and prevent viruses from entering.

b. Drugs that neutralize the acidity of phagolysosomes prevent viral uncoating.

c. Nucleotide analogs can be used to stop microbial replication.

d. Drugs containing protease inhibitors retard viral growth by blocking the production of essential viral proteins.

What specific test for antimicrobial efficacy is shown? What does this test measure? Draw an oval to predict the size and shape of the zone of inhibition if the drug concentration on the strip were increased twofold.

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What characteristics would an ideal chemotherapeutic agent have? Which drug has these qualities?

Contrast narrow-spectrum and broad-spectrum drugs. Which are more effective?

Why is the fact that drug Z destroys the NAM portions of a cell’s wall structure an important factor in considering the drug for chemotherapy?

Given that both human cells and pathogens synthesize proteins at ribosomal sites, how can antimicrobial agents that target this process be safe to use in humans?

Label each of the accompanying figures to indicate the class of drug that is stopping polypeptide translation.

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a. ________________ b. _________________

block initiation. change 30S subunit.

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c. ________________ d. _________________

block ribosome attachment inhibits peptide bonding

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e. ________________ g. _________________

f. ________________ h. _________________

block ribosome movement block tRNA docking

A company that manufactures an antimicrobial cleaner for kitchen counters claims that its product is effective when used in a 50% water solution. By what means might scientists best verify this statement?

a. Disk-diffusion test

b. Phenol coefficient

c. Filter paper test

d. In-use test

The difference between a synthetic drug and a semisynthetic drug is that

a. the semisynthetic drug is a modified synthetic drug.

b. the synthetic drug is a modified natural drug.

c. the synthetic drug is a modified semisynthetic drug.

d. the semisynthetic drug is a modified natural drug.