Question

Give experiments to show that water is necessary for photosynthesis​

Answer 1

Stable isotopes of carbon and hydrogen are useful indicators of the photosynthetic pathway.

Use a hydrogen isotope labelled water to see that the water is split in the photolysis reaction. Then track the hydrogen ions to see where they end up in the plants.

2 (H2O) --- photolysis reaction --> O2 + ATP + NADPH (carrier molecule will transfer H isotope to calvin cycle if water provides the H to build glucose)

NADPH transfers to the Calvin cycle step of photosynthesis and provides the hydrogen to build the CO2 into an organic molecule.

Photosynthesis

CO2 + H2O → → O2 + CH2O

Answer 2

Two plant is kept under the Sun. One plant one plant is watered daily and the other is not. After some days, the plant which is watered well will grow and the other plant with this not wanted all will dry up and die .