Chapter 5, Problem 7WIO

Summary Introduction

To determine:

Where would the ${}^{18}\text{O}$ have ended up if researchers had used ${}^{18}\text{O}$-labeled ${\text{CO}}_2$ instead of ${\text{H}}_{\text{2}}\text{O}$.

Concept introduction:

The hypothetical explanation given by earlier scientists regarding the mechanism of photosynthesis states that oxygen is derived from the carbon dioxide. The remaining carbon atom is added to the water molecule to form glucose. This explanation was challenged by a scientist Van Niel who states that the water splits, and oxygen is released, followed by remaining hydrogen atom combines with carbon dioxide to form glucose.