"dark rxns i.e. calvin cycle can occur without light" why does every other 3rd question no matter what im studying from create problems. as far as i know this is also false. dark rxns are light independant meaning they dont use light directly but atp and nadph can only be produced during photophosphorylation in the light rxn. anybody?
Destroyer bio
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This is false because although the dark reaction does not use light/need light directly, it couples to the light reaction and will not occur unless the light reaction occurs.
Dark reactions do not utilize light in order to occur--HOWEVER, it requires the ATP and NADPH from photophosphorylation in order to occur. Therefore, dark reactions "indirectly" use light. But without light, you won't have photophosphorlyation and in turn, no Calvin Cycle (which occurs in the stroma)!
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sorry but y'alls are wrong. dark reactions can and will occur in the absence of light. once the sun goes down there will still be atp and nadph floating around..the calvin cycle will then occur (for a very short amount of time). this is kind of ridiculous, but at the same time very true.
need more proof? test it in the lab by supplying atp and nadph in the absence of light. [people did this, guess what happened]
is it a really horrible trick question? yes.
is it wrong to say that the dark reactions will not occur in the absence of light? yes
need more proof? test it in the lab by supplying atp and nadph in the absence of light. [people did this, guess what happened]
is it a really horrible trick question? yes.
is it wrong to say that the dark reactions will not occur in the absence of light? yes
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Of course it will occur at night, why else call it the dark reaction? We didn't say it can't happen in the dark. We just said the light reaction must have happened first regardless of the conditions of the dark. Light was necessary at some point for complete photophosphorylation.
The question is definitely tricky in the wording. If it asked: "Can the the dark reaction happen at night", the answer would be yes.
But, "Can the reaction happen without light". NO.
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What everyone here is saying... is not wrong but you have to pay close attention to the wording of the problem. Here I will emphasize it for you.
"dark rxns i.e. calvin cycle can occur without light"
It would be completely different if it said, dark rxns i.e. calvin cycle occurs without light
"dark rxns i.e. calvin cycle can occur without light"
It would be completely different if it said, dark rxns i.e. calvin cycle occurs without light
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sorry bro but thats wrong. as i said before, the proof is that you can supply the necessary ingredients in the lab to make the calvin cycle occur. light has nothing to do with the calvin cycle! light allows the organism to provide the necessary compounds for the calvin cycle, but in no way shape or form do you see light in the reaction if you draw it out.
the key is to understand the "ingredients". light is no ingredient in this reaction [draw it out! i swear], therefore, this reaction can happen without light. i think you are all confusing what NATURALLY OCCURS and what is POSSIBLE.
It seems to be getting kind of muddled when the thread essentially devolves into debate over the word "can." The whole purpose of naming it the dark cycle is that it does not require light to work, i.e. can occur without light, however long that might be until its stores of ATP and NADPH stores are depleted.
I would say dogs can urinate without drinking, but that's where all the liquid content came from. They can urinate until they die of dehydration without drinking any water. Urination can occur without imbibation. Dark reactions can occur without light. You're obsessing too much over the source of nutrition used by the calvin cycle.
I would say dogs can urinate without drinking, but that's where all the liquid content came from. They can urinate until they die of dehydration without drinking any water. Urination can occur without imbibation. Dark reactions can occur without light. You're obsessing too much over the source of nutrition used by the calvin cycle.
