What happens when DCPIP is exposed to light?
What happens when DCPIP is exposed to light?
When exposed to light in a photosynthetic system, the dye is decolorised by chemical reduction. DCPIP has a higher affinity for electrons than ferredoxin and the photosynthetic electron transport chain can reduce DCPIP as a substitute for NADP+, that is normally the final electron carrier in photosynthesis.
Is light necessary for reduction of DCPIP?
The reaction can only occur if the thylakoid membranes are illuminated as the light dependent stage stops in the dark (tube B in the procedure). DCPIP is blue when oxidised (at pH 7.0) and colourless when reduced, so it is possible to monitor the loss of blue colour as an indication that DCPIP has accepted electrons.
What does DPIP do in regards to photosynthesis?
Since DPIP replaces NADPH in the light reactions, it will turn from blue to colorless when reduced during photosynthesis. This will allow you to monitor the rate of photosynthesis. In order to allow the DPIP to come into contact with chloroplasts, the cells will need to be carefully disrupted.
Where is DCPIP reduced in photosynthesis?
DCPIP solution is added to isolated chloroplasts allowing any reducing agent produced by the chloroplasts to be detected. In the cell, NADP is the electron acceptor that is reduced in the light- dependent reactions and provides electrons and hydrogen for the light-independent reactions.
Why does DCPIP turn green?
Tube 5 (supernatant + DCPIP) no colour change if the supernatant is clear; if it is slightly green there may be some decolouring. The results should indicate that the light-dependent reactions of photosynthesis are restricted to the chloroplasts that have been extracted.
Are chloroplasts necessary for the reduction of DCPIP?
In this investigation, DCPIP (2,6-dichlorophenol-indophenol), a blue dye, acts as an electron acceptor and becomes colourless when reduced, allowing any reducing agent produced by the chloroplasts to be detected….Using a micro-centrifuge.
| Time/min | Absorption Tube 1 | Absorption Tube 5 |
|---|---|---|
| 8 | 0.6 | 1.6 |
| 9 | 0.6 | 1.3 |
| 10 | 0.6 | 1.1 |
How does light wavelength affect photosynthesis?
Wavelengths absorbed by chlorophyll and other photosynthetic pigments generate electrons to power photosynthesis. All photosynthetic organisms have chlorophyll a which absorbs violet-blue and reddish orange-red wavelengths. Chlorophyll a reflects green and yellow-green wavelengths.
