Question
Biology Question on Photosynthesis in higher plants
As compared to a C3 plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C4 plants :
A
2
B
6
C
0
D
12
Answer
12
Explanation
Solution
In C4 plants, each CO2 molecule must undergo fixation twice, resulting in a higher energy requirement for the synthesis of hexose sugar molecules compared to C3 plants, where CO2 is fixed only once. C3 plants require 18 ATP molecules to synthesize one molecule of hexose sugar, whereas C4 plants require 30 ATP molecules for the same process. Therefore, C4 plants require an additional 12 ATP molecules compared to C3 plants to produce one molecule of hexose sugar.
So, the correct option is (D); 12