HOW 2,6-DICHLOROPHENOLINDOPHENOL (DCPIP) DAMAGE CHLOROPHYLL CHAIN ELECTRON TRANSPORT, BLOCKING THE PHOTOSYNTHESIS AND PLANT DEAD

This classroom protocol presents a detailed investigation into the dynamics of photosynthesis through practical experiments that explore the effects of light intensity and herbicidal inhibition on the electron transport chain. Using DCPIP (2,6-dichlorophenolindophenol) as a Hill reagent, the reduction kinetics of photosystem II were monitored via changes in absorb-ance at 600 nm under varying light conditions. The experiments demonstrated a direct relationship between irradiance and the electron transport rate, affirming the centrality of photon energy in driving photosynthesis. Additionally, the herbicide Diuron was employed to disrupt the quinone pool, effectively halting the reduction of DCPIP and illustrating its inhibitory impact on photosynthetic processes. The findings, visualized through detailed figures and graphs, highlight the robustness of photosynthetic machinery and its susceptibility to external stressors. These experiments serve as a practical bridge between theoretical concepts and real-world applications. They offer valuable insights into photosynthetic efficiency, the biochemical basis of herbicide action, and their broader ecological implications. By combining spectrophotometric data with analytical observations, the study under-scores the importance of photosynthesis as a cornerstone of plant physiology and its pivotal role in sustaining life on Earth.