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

(N/A) Melvin Calvin used the green alga $Chlorella$ to study the biosynthetic pathway of sugar synthesis.
- He used $C^{14}$ radioactive isotope labeling to trace the path of carbon during photosynthesis.
- He employed the technique of paper chromatography and autoradiography to identify the intermediate compounds.
- He discovered that the first stable product formed during the dark reaction of photosynthesis is a $3$-carbon compound called $3$-Phosphoglyceric acid $(3-PGA)$.
- By further analyzing the chromatograms,he mapped the entire cycle,now known as the Calvin cycle,which leads to the formation of various sugars like hexose,tetrose,and pentose.