Problem 12
To understand how ciprofloxacin works, it's important to be able to visualize the events of DNA synthesis. To help with this, draw a diagram of a replication bubble that shows (1) the \(5^{\prime} \rightarrow 3^{\prime}\) polarity of the two parental DNA strands, (2) the leading and lagging daughter strands at each replication fork, (3) helicase, and (4) topoisomerase.
Problem 13
Ciprofloxacin inhibits DNA gyrase, a bacterial topoisomerase that cuts DNA ahead of the replication fork, winds the DNA in a direction that relieves the twists added during DNA synthesis, and then reseals the DNA. In ciprofloxacin- treated bacteria, newly synthesized DNA is found in fragments. Based on this evidence, what activity of DNA gyrase is likely to be inhibited by ciprofloxacin?
Problem 16
You are a reporter working in 2001 who's just been assigned a story on how ciprofloxacin may save the lives of Senate workers exposed to anthrax. Write a short paragraph that links knowing how DNA is replicated to defense against this act of bioterrorism.
