Question

During the reactions of HSK pathway in bundle sheath chloroplast, malate undergoes ______.

• A. decarboxylation
• B. reduction
• C. phosphorylation
• D. hydration

Hint:

Decarboxylation of malate increases CO$_2$ concentration around RuBisCO.

Answer 1

The Correct Option is A

Step 1: Understanding HSK (C$_4$) pathway.
In C$_4$ plants, malate is transported from mesophyll cells to bundle sheath cells.
Step 2: Reaction in bundle sheath.
Malate undergoes decarboxylation to release CO$_2$, which enters the Calvin cycle.
Step 3: Conclusion.
Hence, malate undergoes decarboxylation.