Question

question 7 of 10
a scientist designs an experiment in which the movement of polar molecules
through a cell membrane is tested. he sets up the following two experiments
in order to collect data on cell membrane permeability. what question is the
scientist most likely trying to answer by conducting this experiment?
experiment 1 experiment 2
polar molecules polar molecules
lipid bilayer lipid bilayer proteins
a. how do polar molecules diffuse across a cell membrane?
b. what role do polar molecules play in the diffusion of proteins
across a cell membrane?
c. how do transport proteins affect the diffusion of polar molecules
across a cell membrane?
d. are polar molecules able to diffuse across a cell membrane at a
greater rate than proteins?

Explanation:

In Experiment 1, there is only a lipid bilayer. In Experiment 2, there are transport proteins in addition to the lipid bilayer. The variable here is the presence of transport proteins. The scientist is likely testing the effect of transport proteins (the added factor in Experiment 2 compared to Experiment 1) on the movement (diffusion) of polar molecules across the cell membrane. So the question is about how transport proteins affect the diffusion of polar molecules across a cell membrane.

Answer:

C. How do transport proteins affect the diffusion of polar molecules across a cell membrane?