Final answer:
Fluoroquinolones target DNA gyrase, preventing bacterial DNA replication and thereby inhibiting bacterial growth, effective against both gram-positive and gram-negative bacteria.
Step-by-step explanation:
Fluoroquinolones primarily target DNA gyrase, an enzyme responsible for unwinding DNA, which is a crucial step for DNA replication. As a result, they effectively inhibit bacterial replication by blocking this process. Specifically, fluoroquinolones such as ciprofloxacin and levofloxacin operate against a variety of gram-positive and gram-negative bacteria making them popular choices for treating numerous infections.