Photosynthesis in plants can be represented by the following overall equation: 

Algae grown in water containing some ¹⁸O (in H₂ ¹⁸O) evolve oxygen gas with the same isotopic composition as the oxygen in the water. When algae growing in water containing only ¹⁶O were furnished carbon dioxide containing ¹⁸O, no ¹⁸O was found to be evolved from the oxygen gas produced. What conclusions about photosynthesis can be drawn from these experiments?

Transcribed Image Text:

H9 6CO₂(g) + 6H₂0 (1) Light C6H₁2O6(s) + 60₂(8)