Question

To determine whether a signal sequence directs proteins to a particular organelle, researchers prepare two versions of the same protein: one version contains the signal sequence, while the other lacks it. They label the protein that contains the signal sequence with a radioactive marker, and then incubate both of the proteins with the organelle of interest. After allowing enough time for any of the proteins to be transported into the organelle, a protease is added to the mixture. If the signal sequence is the correct one for the selected organelle, what would the researchers likely see?

Answer 1

Answer:

The radioactive label would be associated with an intact protein.

Explanation:

Different proteins made by an organism have specialized functions for which they need to travel to the organelles where they have to work. To carry a protein to an organelle, signal molecules are required. The signal molecules interact with the protein molecule and signal them towards the organelle where they need to be transported. Hence, in the experiment conducted above the the protein to which a signal sequence was added will enter the organelle. While the protein in which the signal sequence was not added will be eaten up by the protease.