1. A 68-year-old m an diagnosed w ith streptococcal pneum onia started treatm ent w ith a third-generation cephalosporin. Which of the follow ing steps in the turnover of bacterial cell walls is speci...

1. A 68-year-old m an diagnosed w ith streptococcal pneum onia started treatm ent w ith a third-generation cephalosporin. Which of the follow ing steps in the turnover of bacterial cell walls is speci cally inhibited by this antibiotic? A. Autolysin-m ediated breaking of peptidoglycan chains B. Elongation of linear am ino sugar chains C. Connection of two am ino sugar chains by peptide bridges D. Synthesis of N-acetylm uram ic acid E. Linking of two am ino sugars by a glycosidic bond 2. A 51-year-old wom an recently diagnosed w ith acute bacterial cystitis started an appropriate antibiotic treatm ent. The adm inistered drug achieves therapeutic concentration in the urine because it is prim arily elim inated by the kidney through active secretion in the proxim al tubule. Which of the follow - ing drugs did the patient m ost likely take? A. Cephalexin B. Azithromycin C. Metronidazole D. Tobramycin E. Tetracycline