Question

T/F: each round of the calvin cycle uses 5 molecules of CO2 to produce one molecule of glyceraldehyde 3-phosphate and one pyruvate

Answer 1

The statement "each round of the calvin cycle uses 5 molecules of
`CO_(2)` to produce one molecule of glyceraldehyde 3-phosphate and one pyruvate" is false because each round of the Calvin cycle fixes one molecule of , not five, and three rounds produce one molecule of G3P without producing pyruvate.

Step-by-step explanation:

The statement given is false; each round of the Calvin cycle does not use 5 molecules of
`CO_(2)` to produce one molecule of glyceraldehyde 3-phosphate and one pyruvate. In fact, the Calvin cycle operates in a way that three turns are needed to fix three molecules of
`CO_(2)`, resulting in one molecule of
`G_(3)P`. This
`G_(3)P` can then be used to form various carbohydrates, including glucose.

Energy-wise, the Calvin cycle requires an input of 9 ATP and 6 NADPH for three turns to produce one
`G_(3)P` molecule. Specifically, 6 ATP and 6 NADPH are utilized in the reduction phase while an additional 3 ATP are used in the regeneration phase of
`R_(u)BP`. The final product after three turns is one molecule of
`G_(3)P`, which is a three-carbon sugar. However, it takes six turns of the Calvin cycle to produce a six-carbon glucose molecule, which requires a total input of 18 ATP and 12 NADPH.