How is photosynthesis similar in C4 plants and CAM plants?
a. In ...

Question

How is photosynthesis similar in C4 plants and CAM plants?
a. In both cases, the light reactions and the Calvin cycle are separated in both time and location.
b. Both types of plants make sugar without the Calvin cycle.
c. In both cases, rubisco is not used to fix carbon initially.
d. Both types of plants make most of their sugar in the dark.

Accepted Answer

Hi everyone. Let's look at our next problem here, it says which of the following characteristic features is not true concerning both c. four plants and cam plants. Well let's recall from our content video that c. four plants and cam plants have both evolved an alternate method of carbon fixation and that's to deal with hot and dry conditions, allowing them to have their systematic closed at times to minimize water loss through this tomato. And of course in C. Three plants. When Samana are closed, you run the risk of bumping rube. Isco into photo respiration where it fixes oxygen instead of CO. Two as oxygen concentration increases and so too decreases the romesco is more likely to perform photo respiration, which is much less efficient than the Calvin cycle. But when this tomato close, that's precisely what happens. You're not getting any new C. 02 through this tomato since that's where gas exchange occurs. And as the Calvin cycle proceeds, you're consuming C. 02 and producing 02, resulting in decreasing concentrations of CO two and increasing concentrations of 02. So in C. Four plants and cam plants, both have separated the process of carbon fixation from the process of the Calvin cycle in an attempt to maintain high CO two concentrations around Biscoe and prevent photo respiration. But they have two separate methods C4 plants separate carbon fixation and Calvin cycle in space, carbon fixation takes place in the mesophyll cells. These are on the outer part of the leaf where the tomatoes are and then Calvin cycle takes place in special cells called bundle sheath cells. These are on the interior of the leaf. So the disco is isolated from any oxygen coming from the atmosphere. So carbon is fixed in the mesophyll cells by the enzyme pep car box Alice instead of disco. That delivers a molecule of oxygen O. Acetate to the bundle sheath cells where it releases a C. 02. That can then proceed react through Biscoe and proceed into the Calvin cycle. Cam plants separate these two processes in time. They closed their stamina during the day, so carbon fixation only happens at night and then the Calvin cycle proceeds with C. 02. That's been fixed at night during the day. So with that in mind, with similarities and differences between our c. four and cam plants. Let's look at our answer choices. So Choice A says photosynthesis is efficient even in hot temperatures. Well, this is true of both C. Four and cam plants. They both separate this process. They're able to close their store Mata and still have photosynthesis taking place in the more efficient Calvin cycle. So it's true of both. Since we're looking for the statement that's not true about both. Choice A is not our answer choice B says photo respiration is suppressed. That's also true of both. Again, the goal of separating carbon fixation in the Calvin cycle is that you prevent disco from building up high concentrations of oxygen around it, which would cause photo respiration. So, Choice B is not an answer Choice. E says the state motto is open during nighttime. Well, that is true only of cam plants. C4 plants do have their stamina open during the day, but not all the time. They can close when it's particularly hot, particularly dry. So this is our answer. As this is not true of both, but only cam plants. And finally, Choice D. Says in both cases, pep car box Alice is used to fix carbon initially. This is true of both. That's the alternate enzyme used instead of rope disco for carbon fixation. So Choice D. Is not our answer. So again, which feature is not true concerning both c. four plants and cam plants. Choice see the tomato is open during the night time. See you in the next video.

Key Concepts

Photosynthesis

C4 and CAM Pathways

Rubisco

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