Glucose is made from the trioses (3-carbon sugars) in plants according to the usual gluconeogenesis pathway. That is, glyceraldehyde phosphate is converted to fructose-1,6-diphosphate by triose phosphate isomerase and aldolase, and then dephosphorylated to obtain hexose phosphat

3-PGA ($\ce{C_6H_7O_7P}$) is converted to G3P ($\ce{C_6H_7O_6P}$) before it is able to be made into glucose, with an expansion of 6 ATP and 6 NADPH. My question is why this process is needed and why the loss of 1 oxygen atom decides whether a …

2021年10月6日 · $\begingroup$ @David Added; I think the question is pretty clear. Textbooks often say you need "6 runs" through the Calvin cycle to make glucose; this makes a lot of sense because you're taking in one carbon through CO2, so to make a 6-carbon sugar you need to do something 6 times.

2015年5月24日 · Around 6 molecules of G3P is produced at the end of the Calvin Cycle (light independent reactions of photosynthesis), and 5 of which are reverted back to RuBp. The general equation that I read is 5 G3P -----> 3 RuBp using 3 ATP. It however doesn't seem to add up (regarding balancing of the atoms) as 5 phosphates would be converted to 6.

2022年6月6日 · $\begingroup$ Or why a sugar at all? CO(2) is the most oxidized form of a single carbon atom, and in photosynthesis carbon is reduced (where water is the source of electrons), but not fully reduced: the most reduced form of a C-6 compound is hexane, not glucose (and the most reduced form of a single carbon atom is methane) $\endgroup$

2014年12月8日 · During Calvin cycle, 3 molecules of CO2 combine with RuBP acceptors to form 6 molecules of G3P. 1 G3P molecule exits the cycle and goes towards making glucose while the other 5 are recycled, regenerating 3 RuBP acceptor molecules. Plants do synthesise glucose.

2017年2月26日 · The quick answer is "both", but the stoichiometry is not 1-to-1. The stoichiometry of the calvin cycle doesn't add up when thinking about a single molecules making one "turn" of the cycle.

2021年7月22日 · One source shows that "the carbohydrate products of the Calvin cycle are three-carbon sugar phosphate molecules, or 'triose phosphates', namely, glyceraldehyde-3-phosphate (G3P)." Are F6P and E4P also carbohydrates? Are ALL n-carbon sugar phosphate molecules classified as carbohydrates?

2016年4月19日 · The GP molecules are phosphorylated by ATP and reduced by NADPH+H+. The GP molecules are then converted into triose phosphates (TP) called glyceraldehyde phosphate. From the 6 molecules of TP which are created, only 1 is used to form/create half of a sugar (this means 2 cycles are required to construct a full sugar).

2015年4月25日 · $\begingroup$ So you hydrolyzed 18 ATP, and if you look at the calvin cycle, for each CO2 that enters the cycle, you use up 2 ATP in the formation of G3P and 1 ATP in the regeneration of rubisco. So 18/3 = 6, and that would coincide with the entry of 6 CO2 into the cycle, or the normal photosynthesis equation.