Question

Which of the following products of the light reaction are assimilated in dark reaction?
I. Reduced NADP (NADPH)
II. ATP
III. \[O_2\]

A. I only
B. II only
C. III only
D. I and II only
E. I, II and III

Answer 1

Hint: The light reaction is the first stage in the process of photosynthesis where solar energy in the form of ATP and NADPH is converted into the chemical energy. The protein complexes and the pigment molecules contribute to NADPH and ATP production.

Complete Answer:
- The light reaction is known as the photolysis reaction which occurs in the presence of light. It is commonly done in the grana. Pigment molecules are present in the photosystems. Chlorophyll is one of the primary pigments that participate actively in the light reaction process such as photosynthesis in plants.
- Carotenoids are used in the accessory pigments. Chlorophyll absorbed the energy from the sun by the chloroplast thylakoid membrane. The energy is then transferred through the two-electron transport chains to ATP and NADPH. During the process, water is used and oxygen is released.
- The light reaction is the first stage in the process of photosynthesis where solar energy in the form of ATP and NADPH is converted into the chemical energy. The protein complexes and the pigment molecules contribute to NADPH and ATP production.
- The Calvin cycle, light-independent reactions, bio-synthetic process, dark reactions are the chemical reactions that transform carbon dioxide and any other component into glucose. These reactions happen in the chloroplast stroma region outside the thylakoid membranes, the fluid filled region.
- These reactions take the light-dependent reactions of ATP and NADPH products and carry out additional chemical processes. The dark reaction uses ATP and NADPH reduction forces from light reactions to create sugars for the plant.

Thus, the correct answer is option D. i.e, I and II only.

Note: Splitting the water molecule into oxygen and discharging electrons reduces NADP into NADPH. NADPH and ATP are used to fix carbon dioxide into carbohydrates during dark reactions as an energy source. Oxygen is the by-product of light reactions and does not be absorbed in the dark.