Explain the increase in mass of the light-grown plants. In your explanation, id

Explain the increase in mass of the light-grown plants. In your explanation, identify an inorganic source of new plant mass and connect it to the cellular process underlying the increase in mass. 
Explain the decrease in mass of the dark-grown plants. Identify the overall chemical reaction that is taking place in these plant cells and connect it to the cellular process underlying the decrease in their mass.