PHOTOSYNTHESIS
C 4 PHOTOSYNTHESIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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They use PEP carboxylase to initially fix CO2
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They conserve CO2 more efficiently.
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They exclude oxygen from their tissues.
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They do not participate in Calvin cycle.
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Detailed explanation-1: -C4 plants use a more efficient enzyme than rubisco . This enzyme allows for little to no oxygen fixation and much more carbon fixation (in other words, less photorespiration).
Detailed explanation-2: -In C4 photosynthesis, where a four-carbon compound is produced, unique leaf anatomy allows carbon dioxide to concentrate in ‘bundle sheath’ cells around Rubisco. This structure delivers carbon dioxide straight to Rubisco, effectively removing its contact with oxygen and the need for photorespiration.
Detailed explanation-3: -In the C4 pathway, initial carbon fixation takes place in mesophyll cells and the Calvin cycle takes place in bundle-sheath cells. PEP carboxylase attaches an incoming carbon dioxide molecul to the three-carbon molecule PEP, producing oxaloacetate (a four-carbon molecule).
Detailed explanation-4: -What is the role of PEP carboxylase in C4 and CAM plants? PEP carboxylase is essential for carbon fixation in C4 and CAM plants. It is present in the mesophyll cells. It catalyses the initial carbon fixation where PEP acts as an acceptor for CO2, and produces OAA.
Detailed explanation-5: -PEP carboxylase, which is located in the mesophyll cells, is an essential enzyme in C4 plants. In hot and dry environments, carbon dioxide concentrations inside the leaf fall when the plant closes or partially closes its stomata to reduce water loss from the leaves.