PHOTOSYNTHESIS
THE CALVIN CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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3
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6
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12
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16
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Detailed explanation-1: -… two molecules of phosphoglycerate (PGA), a three-carbon acid. Each reaction is catalyzed by a specific enzyme. Six revolutions of the cycle means that 6 CO2 molecules react with 6 RuBP molecules to produce 12 molecules of PGA; 2 three-carbon PGA molecules combine to form the six-carbon glucose, and 10…
Detailed explanation-2: -The unstable 6 carbon compound splits into two molecules of 3-PGA. Hence, for every one CO2 molecule fixed, two molecules of 3-PGA are produced.
Detailed explanation-3: -3-PGA has three carbons and one phosphate. Each turn of the cycle involves only one RuBP and one carbon dioxide and forms two molecules of 3-PGA.
Detailed explanation-4: -RuBP combines with CO2 and forms an unstable compound that splits into two molecules of 3-PGA. So, two molecules of 3-PGA (3-phosphoglycerate) are synthesized for every CO2 fixed in the Calvin cycle. For the synthesis of one molecule of glucose, 6 carbon dioxide molecules are required and hence six Calvin cycles occur.
Detailed explanation-5: -Every 3 cycles of the Calvin Cycle (light independent reaction), 6 molecules of G3P are produced; only 1 is used to produce glucose. The remaining 5 molecules of G3P are used to regenerate RuBP to allow the Calvin Cycle to continue.