Title: What is the C4 pathway? Briefly explain how this adaptation increases the effectiveness of ... Post by: ornobtizzi on Mar 29, 2018 What is the C4 pathway? Briefly explain how this adaptation increases the effectiveness of
photosynthesis in these plants. What will be an ideal response? Question 2 Explain the origin, location, and function of the proton gradient in the process of photosynthesis. What will be an ideal response? Title: What is the C4 pathway? Briefly explain how this adaptation increases the effectiveness of ... Post by: blvan on Mar 29, 2018 In the C4 pathway, CO2 reacts with PEP in a reaction catalyzed by PEP carboxylase, and oxaloacetate is formed as the product. This reaction occurs in mesophyll cells. In turn, oxaloacetate is converted to malate, the malate diffuses into bundle sheath cells, and is decarboxylated to pyruvate. The CO2 thus formed enters the Calvin cycle. The C4 pathway enables photosynthesis to occur more efficiently in hot, dry environments when plants normally close their stomata to prevent water loss. In such cases, the C3 pathway is inhibited because the O2 that accumulates in photorespiration outcompletes low levels of CO2 for the active site of RuBP carboxylase/oxygenase. However, because PEP carboxylase binds only CO2 and not O2, plants having the C4 pathway can thrive when the CO2 levels are low The proton gradient is established in the thylakoid lumen as electrons flow down the photosynthetic electron transport chain. As the electrons lose energy some of that energy is used to pump protons across the thylakoid membrane into the lumen. As the protons accumulate, they form a gradient, with the proton concentration in the lumen higher than in the stroma. Eventually the protons flow downhill through the ATP synthase complex in the thylakoid membrane. The exergonic process of diffusion down this gradient is used to power the endergonic process of ATP synthesis Title: What is the C4 pathway? Briefly explain how this adaptation increases the effectiveness of ... Post by: ornobtizzi on Mar 29, 2018 Thank you for helping me throughout this difficult semester
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