the radioactive isotope 32p labels the t2 phage’s _____.
What is labeled by the radioactive isotope 32p in the T2 phage?
Answer: The radioactive isotope ^32P, or phosphorus-32, labels the T2 phage’s DNA. This is because DNA contains phosphorus as part of its backbone structure (in the phosphate groups), whereas proteins do not. In the classic Hershey-Chase experiment conducted in 1952, ^32P was used to label the DNA of bacteriophages to demonstrate that DNA, not protein, was the hereditary material transferred to bacteria during viral infection.
Key Points:
-
Phosphorus in DNA: DNA contains phosphorus, particularly in its phosphate groups that form part of the backbone of the DNA structure.
-
Hershey-Chase Experiment: In this experiment, ^32P was used to track the movement of DNA from the T2 phage into the bacterium E. coli. The experiment conclusively showed that DNA, not protein, is the genetic material that viruses use to replicate within host cells.
-
Purpose of Labeling: By using a radioactive isotope, scientists could trace exactly where the DNA went during the infection process, verifying that it wasn’t the protein, which does not contain phosphorus, being transferred.
Summary: The radioactive isotope ^32P labels the T2 phage’s DNA. This labeling was crucial for confirming the role of DNA as the genetic material during virus infection in the Hershey-Chase experiment.