dcpip (2,6-dichlorophenol-indophenol), a blue dye, can act as an electron acceptor and becomes colorless when reduced. a suspension of chloroplasts is prepared, and dcpip is added to the suspension. the sample is split into two test tubes. one test tube is exposed to light and the other is wrapped in foil (dark control). what would you observe over time comparing the light exposed and the dark control test tubes?
In the light-exposed test tube, you would observe a gradual change in color from blue to colorless as the dcpip is reduced by the chloroplasts. This is because the chloroplasts are able to carry out photosynthesis in the presence of light, producing electrons that can be transferred to dcpip, causing it to become colorless.
In contrast, in the dark control test tube, where the chloroplasts are not exposed to light, there would be no significant change in color over time. This is because photosynthesis cannot occur without light, so the chloroplasts would not be able to produce the electrons necessary to reduce the dcpip, resulting in no color change.
Thus, the light-exposed test tube would show a gradual color change from blue to colorless, while the dark control test tube would remain blue.