Question

Question 38
Find out how Melvin Calvin worked out the complete biosynthetic pathway for synthesis of sugar.

Answer 1

Melvin Calvin used Chlorella as an experimental material and discovered the first stable compound of photosynthesis, i.e., 3 phosphoglyceric acid so as to trace the path of carbon by using a radioactive isotope of carbon $\left(C^{14}\right)$ and autoradiography technique.
He then, compared the radioactive compounds on the chromatogram as result of which he found and concluded that the PGA (phosphoglyceric acid), as the first stable product of photosynthesis and gradually the other sugars including hexoses, tetroses and pentoses etc.
Thus, he derived the pathway of $\left(C{O}_2\right)$ fixation from these radioactive products (sugars) formed.