What happens to the energy carriers once they have been spent in the reduction stage?
AThey return to the light-dependent reactions
BThey are broken down and thrown out of the cell
CThey are stored in the stroma until nightfall
DThey are converted into carbohydrate molecules
Answer & Solution
Correct answer: A. They return to the light-dependent reactions
1. Adenosine triphosphate loses its terminal phosphate and becomes adenosine diphosphate.
2. NADPH loses both energy and a hydrogen atom, becoming the oxidized carrier again.
3. Both of these molecules return to the nearby light-dependent reactions to be reused and reenergised.
4. This is why the carriers are described as arriving full and going back empty.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 8 "Photosynthesis", section 8.3 Using Light Energy to Make Organic Molecules_
Related questions
The light-independent reactions still depend on the light reactions because they need:Roughly what share of the oxygen produced in a leaf is used by the leaf's own mitochondriaLight of energy higher than blue damages pigment molecules in a process called:Bacteria that build sugars using energy from inorganic chemicals rather than light are:The coal and petroleum burned today store sunlight captured by photosynthesis roughly:How many turns of the Calvin cycle are needed before one G3P leaves it?The three-carbon carbohydrate that carbon dioxide is first fixed into is:The flow of hydrogen ions through ATP synthase is called: