CH 12 test bank-microbiology

CH 12 test bank-microbiology Substances that are naturally produced by certain microorganisms that can inhibit or destroy bacteria are called ______. antibiotics Antimicrobials effective against a wide variety of microbial types are termed ______. broad-spectrum drugs Antibiotics are derived from all of the following, except ______. Staphylococcus 4. Important characteristics of antimicrobial drugs include A. low toxicity for human tissues. B. high toxicity against microbial cells. C. a lack of serious side effects in humans. D. stability and solubility in body tissues and fluids. E. All of the choices are correct. An ideal antimicrobial therapeutic drug exhibits all of the following characteristics, except they are easily broken down by host. 6. The use of a drug to prevent imminent infection is called ______. prophylaxis 7. The use of any chemical in the treatment, relief, or prophylaxis of a disease is called ______. chemotherapy 8. Penicillins and cephalosporins block peptidases that cross-link glycan molecules. Each of the following affect cell walls, except ______. erythromycin Selective toxicity refers to damage to the target organisms but not vertebrate cells. Aminoglycosides attach to the 30S ribosomal subunit and disrupt protein synthesis. Each of the following target bacterial ribosomes, except ______. polymyxins Antibiotics that disrupt bacterial ribosomes can also affect eukaryotic mitochondrial ribosomes. Drugs that insert on the _____ ribosomal subunit prevent peptide bond formation or inhibit translocation of the subunit during translation. 50S Which of the following antimicrobials does not inhibit DNA synthesis? Penicillin Sulfonamides are metabolic analogs of PABA and block folic acid synthesis. Sulfa drugs work on folic acid biosynthesis. Sulfonamides are analogs of PABA and, as a result, they inhibit _____ synthesis. folic acid Drugs that act by mimicking the normal substrate of an enzyme, thereby blocking its active site, are called______. competitive inhibitors Ampicillin, amoxicillin, mezlocillin, and penicillin G all have ______. a beta-lactam ring A chemical that inhibits beta-lactamase enzymes is ______. clavulanic acid What molecule will allow some bacteria to be resistant to many penicillins? Penicillinase All of the following pertain to cephalosporins, except they are are synthetic drugs. Which antimicrobial does not inhibit cell wall synthesis? Gentamicin Which drug is used to treat cases of tuberculosis? Isoniazid What drug is used in cases of penicillin and methicillin resistance and also used to treat endocarditis? Vancomycin Clavulanic acid inhibits beta-lactamase activity All _____ consist of a thiazolidine ring, a beta-lactam ring, and an R group penicillins A major source of naturally produced penicillin is the mold ______. Penicillium chrysogenum What antibiotic is mixed with neomycin and polymyxin to make an antibiotic ointment (Neosporin) for superficial skin infections? Bacitracin Infections caused by gram-negative bacilli are often treated with ______. aminoglycosides Which antimicrobial does not interfere with protein synthesi