By this time the green pigment found in green plants had been named chlorophyll . The role of light energy lead to the food-making process in plants being called photosynthesis . Scoring criteria Explain the difference between a philosopher and a scientist. While the equation above looks like a simple one step reaction, there are actually quite a few steps between the reactants and products. This system depends on sunlight for activation energy.
Water is split, giving off oxygen.
While this system depends on the products from the light reactions, it does not directly require light energy. Energy from the light reaction is used to convert carbon dioxide into a series of carbon sugars. The ultimate product is glucose. 55 H 70 MgN 4 O 6 . This molecule is called a pigment because it absorbs certain wavelengths of light.