Question

1. Were chloroplasts able to reduce DPIP in blue light? In green light? In red light? Explain.

Answer 1

ANS. Using DPIP As an Electron Acceptor. When light strikes the chloroplasts, the DPIP is reduced by the excited electrons from chlorophyll, and it changes from its original blue color to colorless as it accepts the electrons.

Green light is the least effective for plants because they are themselves green due to the pigment Chlorophyll. Different color light helps plants achieve different goals as well. Blue light, for example, helps encourage vegetative leaf growth. Red light, when combined with blue, allows plants to flower.

The green pigment, chlorophyll, plays a central role in photosynthesis. Red wavelengths are lower in energy and only boost the electron to a lower energy level than can blue light. This stable excitation state is responsible for the red absorption peak.

The function of the DPIP is to change from blue to clear as photosynthesis proceeds and DPIP is reduced, allowing the spectrometer to measure the rate of photosynthesis through the clarity of the DPIP solution. The DPIP replaces the NADP+ molecules in photosynthesis. The source of the electrons is the water.