Question

A Western blot to detect arrestin levels is performed on proteins harvested from rod cells that are either dark adapted or light adapted. What do they expect to see?____

a. a band of greater intensity in the dark-adapted cell sample, which is explained by increased rhodopsin signaling
b. a band of weaker intensity in the dark-adapted cell sample, which is explained by decreased rhodopsin signaling
c. a band of greater intensity in the dark-adapted cell sample because in these cells the arrestin protein is inactive
d. bands of equal intensity between the two cell populations due to the fact that while arrestin activity is different, the protein levels are not
e. More information is needed.

Answer 1

They expect to see a band of weaker intensity in the dark-adapted cell sample, which is explained by decreased rhodopsin signaling.Option B is the answer.

Step-by-step explanation:

In dark-adapted rod cells, rhodopsin signaling is active, leading to the activation of arrestin. Arrestin binds to phosphorylated rhodopsin, which desensitizes the cell to further signaling. Therefore, in the dark-adapted state, one would expect a weaker band intensity in the Western blot due to decreased rhodopsin signaling. The decreased intensity reflects the binding of arrestin to rhodopsin, indicating a downregulation of the signaling cascade.

Options a and c are not consistent with the expected outcome. Option d is incorrect as the activity of arrestin does influence the band intensity in Western blotting. Therefore, option b best aligns with the physiological processes associated with rhodopsin signaling in dark-adapted cells.

Option B is the answer.