question_answer

A scientist discovered that a protein associated with the plasma membrane of a cultured animal cell disappeared from the membrane soon after a hormone was added to the cell. After adding the hormone, if she disrupted the cell and centrifuged it, the protein did not stay in solution but went to the bottom of the centrifuge tube. After adding the hormone, if she disrupted the cell and dissolved all membranes with a detergent before centrifuging, the protein remained in solution. Which statement best explains her results?

A)  The protein was a peripheral membrane protein that came off the membrane after hormone treatment.

B)  The hormone caused the cell to make endocytotic vesicles that specifically formed at sites in the plasma membrane that contained the protein.

C)  The hormone destroyed the protein.

D)  The hormone bound to the protein to make the protein heavier.