A Researcher Is Carrying Out an Experiment Where She Labels

Multiple Choice

A researcher is carrying out an experiment where she labels a protein with a fluorescent tag (so she can visualize its location in a cell) , and introduces this tagged protein into the lumen of a single thylakoid. She observes her treated cells periodically, and notices that the labeled protein can move between grana, but is never observed in the stroma. What can she deduce?

A) This protein can easily transfer between the inner and outer mitochondria membranes.
B) All thylakoid membranes and grana share a common lumen, through which the labeled protein can move.
C) This protein likely travels between different thylakoid membranes by moving through the stroma, but its movement through the stroma is very brief.
D) This protein cannot easily diffuse through the thylakoid membrane.
E) The protein likely travels through a common lumen shared by thylakoid membranes and grana, and cannot easily diffuse through the thylakoid membrane.