Question

Photochemical reactions of photosynthesis occur in:-
A) Grana lamellae and stroma lamellae of chloroplast
B) Grana lamellae and the fluid stroma of chloroplast
C) Stroma lamellae and the fluid stroma of chloroplast
D) The fluid stroma of chloroplast

Answer 1

Hint: A photochemical reaction is a chemical reaction caused when a substance's molecules consume light energy. It occurs where the stacks of Thylakoid.

Complete answer:
Photochemical reaction, a chemical reaction caused in the presence of light by the absorption of radiation. The effect of the absorbing light of molecules is the formation of transient excited states whose physical and chemical features vary considerably from the original molecules.
Now, let us find the solution from the options-
Photochemical reaction is a chemical reaction in plants where light in the form of energy is consumed and electrons emitted are used to generate energy and perform various functions. In grana or stroma lamellae have stacks of thylakoid where the photosynthetic pigments are located and this photochemical reaction takes place. The energy that is released by the light reaction goes to a stroma region where carbon is found, then it will fix the carbon and contribute to glucose production.
From these we came to know that option B, C, and D are incorrect.

Thus, the correct answer is option (A) Grana lamellae and stroma lamellae of chloroplast.

Note: Photochemistry is a branch of chemistry that primarily deals with the reaction rates and processes arising from reactant exposure to light radiation. The photochemical reaction is essentially the thermal reaction of the molecule's electronically excited state, while the thermal reaction of the ground state is the dark reaction of the molecule.