Question

Synthesis of \( \text{ADP} + P_i \rightarrow \text{ATP} \) in grana is:

• A. Phosphorylation
• B. Photophosphorylation
• C. Oxidative phosphorylation
• D. Photolysis

Hint:

Grana → Light reaction → Photophosphorylation
Stroma → Dark reaction → Calvin cycle Always link the process with the correct chloroplast structure.

Answer 1

The Correct Option is B

Step 1: Recall the structure and function of grana. Grana are stacks of thylakoid membranes present in the chloroplast. They are the site of the light-dependent reactions of photosynthesis.
Step 2: Identify the process occurring in grana. During the light reaction:
Light energy is absorbed by chlorophyll,
Energy is used to synthesize ATP from ADP and inorganic phosphate (\(P_i\)). This process is called photophosphorylation.
Step 3: Eliminate incorrect options.
Phosphorylation: General term, not specific to light reactions.
Oxidative phosphorylation: Occurs in mitochondria during respiration.
Photolysis: Splitting of water into \(H^+\), \(O_2\), and electrons.
Hence, the correct answer is \[ \boxed{\text{Photophosphorylation}} \]