Flaveria Case

Decent Essays

1. Why is the genus Flaveria a good model to study photosynthesis? The genus Flaveria is a good model to study photosynthesis because the plant is going through evolutionary changes with some species in their C4, C3 and C4&C3 in-between (intermediates) states lead to tracing its genetics .

2. What is photorespiration and why is it a problem in C3 plants? Photorespiration is located in the mesophyll cells and happens when the plant is in hot conditions leading to the stroma to close off preventing water loss (cause plants shrink) and not preventing O2 to diffuse through the cell. Thus creating and uptake in the concentration of O2 leading to the RuBP to bonded to O2 instead of CO2 producing a molecule that is useless to the cell while not …show more content…

How have C4 plants solved the problem of photorespiration? C4 plants solved the problem of photorespiration by using new methods involving special bundle sheath cells. So as the CO2 diffuses into the mesophyll cell in goes to a number of transformations ultimate leading to the formation of Glycine. Then Glycine is transported to the bundle sheath cells where the Calvin Cycle is completed. Furthermore, the bundle sheath has a low concentration of oxygen and high concentration of carbon dioxide which in turn does not allow the Rubisco to have a chance of bonding to oxygen allowing for the overall production of glucose.

4. What is the photorespiratory pump and what does it do in C3-C4 intermediates? The photorespiratory pump refers to the transport of the of the Glycine into the Bundle Sheath. In C3-C4 intermediates, photorespiration by refixing photorespired CO2 released in the bundle sheath cell allowing for there to be a concentration of CO2.

5. Why is establishment of a photorespiratory pump considered a key evolutionary step in the transition from C3 to C4 photosynthesis? The establishment of the photorespiratory pump is considered a key evolutionary step in the transition from C3 to C4 photosynthesis because the pump mostly eliminates the photorespiration of a plant from …show more content…

What is the role of glycine decarboxylase enzyme in the photorespiratory pump in C3-C4 intermediates? What reaction does it catalyze and how does it make photosynthesis more efficient in the C3-C4 intermediates? Why is it a benefit for C3-C4 intermediates to produce this enzyme in the bundle sheath cells? Glycine decarboxylase enzyme(GDC) gene is expressed in a different way in C3-C4 intermediates which makes them only produced in the bundle sheath. The role of GDC is to decarboxylate Glycine thus leading to Oxygen being used in the Calvin Cycle. It is beneficial to produce this enzyme in the bundle sheath because it is impermeable to CO2 allowing for there to be a high concentration within the breadth sheath in turn preventing O2 from interfering with the cycle. This makes Photosynthesis more efficient because the cycle will produce a carbohydrate at the end instead of a molecule that has no benefit to the

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