Question

During what stage of photosynthesis are \[NADP^+\] and ADP + Pi converted to ATP and NADPH?
A. the light-dependent reactions.
B. The light-independent reactions.
C. Both (A) and (B).
D. None of the above.

Answer 1

Hint: Photosynthesis is an energy forming process by the plants in chloroplast organelle. In this process plants fix the atmospheric carbon dioxide with water by capturing the radiant energy that comes from the sun. Plants convert the radiant energy into the chemical energy and make available for the other organism of the ecosystem of the earth

Complete answer:
The photosynthesis reaction associated with two types of reaction, which take place in two different parts of the subcellular organelle. The name of the reaction is a light-dependent reaction and the second is a light-independent reaction.
a. Light-dependent reaction:- This is also called hill reaction which takes place inside the thylakoids, in grana. It requires light, this phase produces assimilatory power that consists of reduced coenzymes NADPH and ATP molecules. This phase involves the photolysis of water and the generation of assimilatory power (NADPH and ATP). The conversion of \[NADP^+\] and ADP+ Pi converted to ATP and NADPH is called photophosphorylation, which occurs in the second step of light reaction after photolysis of water molecule, the electron comes from the photolysis of water is going to reduce the \[NADP^+\] molecule to NADPH by the help of carrier molecule and reductase enzyme. Both NADP and ADP converted into NADPH and ATP.
b. Dark reaction:- It is called Blackman’s reaction and biosynthetic phase. This reaction takes place in the stroma of the chloroplast and does not require light, this reaction uses assimilatory power (ATP and NADPH) in fixation and reduction of carbon dioxide.
Hence, the correct Option is A.

Note: Chloroplast is the green plastid that functions as a site of photosynthesis and these plastids contain a photosynthetic pigment which entraps the light for photosynthesis. The chlorophyll a, b, c, d, e, and carotenoid, which are present alone or with combinations in the different organisms (photosynthetic bacteria).