How would the results of the hersheychase experiment have been different if protein were the genetic material?

Answer 1

The experiment would simple prove them wrong and prove that DNA is the genetic carrier.

Answer 2

A little background knowledge: Hershey and Chase's experiment basically sought to determine whether proteins or DNA was the genetic material. In order to do so they used bacteriophages (viruses that infect bacteria), based on prior research which indicated that these viruses injected whatever the mystery genetic material was into the cell. Hershey and Chase used tagged the bacteriophages with radioisotopes (radioactive forms of the elements) of phosphorus and sulphur; phosphorus being a major part of DNA and sulphur being a major part of proteins. Hershey and Chase allowed these bacteriophages to infect a collony of bacteria and then centrifuged the bacteria to remove the casings of the bacteriophages from the surface of the bacterial cells. What they found was that the radioisotopes of phosphorus were inside the cells, meaning that DNA had been trasfered into the cell, and not the sulphur. Because the casings of the bacteriophages are protein based, they are where the majority of the sulphur radioisotopes ended up.

So what if it turned out that proteins were the genetic material: Let's say that we found life on another planet and we wanted to perform a similar test to what Hershey and Chase did. If the genetic material for this new life form were proteins instead of DNA, what could we expect to see as a result from this experiment? In a test using protein based bacteria and protein based bacteriophages, we would assume that instead of DNA being injected into the bacterial cells it would be proteins.

We would then expect to find radioactive sulphur inside the cells, as it would be the proteins (which contain sulphur) which would be injected into the cell. And no radioactive phosphorus would be detectable within the cells.

The bottom line: If proteins were the genetic material, as opposed to DNA, we would expect radioactive sulphur to be detectable within the cells of the Hershey-Chase experiment as opposed to phosphorus.