When wheat and sugarcane leaves are fed with radioactive `.^(14)CO_(2)`. In which molecule would the radioactivity appear first in these plants?

Options

A. 3-Phosphoglycerate Oxalocacetate
B. 3-Phosphoglycerate 3-Phosphoglycerate
C. Oxalocaetate Oxaloacetate
D. Malate 3-Phosphoglycerate

Answer

A

Explanation

Wheat is a `C_(3)` plant and sugarcane is a `C_(4)` plant. In a `C_(3)` plant, first product of photosynthesis is3-phosphoglycerate whereas in a `C_(4)` plant, first product of photosynthesis is a 4-C organic acid i.e., oxaloacetic acid which is reduced to malic acid (malate) or transaminated to form aspartate. In second, more than `94%` of fixed radioactivity if ound to be present in malate, aspartate and oxalocetate.