Electron Transport Through Photosystem I Stimulates Light Activation of Ribulose Bisphosphate Carboxylase/Oxygenase (Rubisco) by Rubisco Activase Essay
Campbell WJ, Ogren WL (1990) Electron transport through photosystem I stimulates light activation of ribulose bisphosphate carboxylase/oxygenase (rubisco) by rubisco activase. Plant Physiol. 94: 479-484
Rubisco is an enzyme that is involved in the Calvin cycle of photosynthesis. It is responsible for catalyzing the formation of 3-phosphoglycerate from RuBP and Co2 and needs the system of Rubisco activase, in which ATP is necessary to perform its job. The author’s main goal of conducting this experiment is to determine the specific area that is responsible for the increase of Rubisco’s light activation. The authors obtained chloroplast from spinach and diluted them appropriately, ensuring that they were exposed in physiological concentration of CO2 (10µm). Rubisco was first deactivated by exposing it in a dark environment for 5 minutes and then reactivated to start measuring the oxygen evolution which was a way to assess electron flow. After adding RuBP, several different electron donors, acceptors and inhibitors were utilized at different areas at the thylakoid membrane to help determine the particular location which/that? increased Rubisco’s activation. This was essential to analyze the effects/affects/influence of photosystem II and photosystem I separately on the activation of Rubsico. For instance, DCMU and DBMIB played a role in inhibiting the electron pathway involving PSII and PSI, respectively. DHQ and DCPIP/ascorbate were added for the purpose of donating
