The mechanism of action of many common medications involves interfering with the normal pathways that cells use to respond to hormone signals. Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway?
A. A medication interrupts the transcription of ribosomal RNA genes.
B. A medication enters the target cell and inhibits an enzyme that normally synthesizes a second messenger.
C. A medication causes the cell to absorb more of a particular mineral, eventually poisoning the cell.
D. A medication enters the target cell's cytoplasm and acts as a mutagen.
Answer: B