Answer: Light is absorbed during the light dependent reactions while sugar is produced during the carbon fixation or carbon dioxide assimilation reactions.
Explanation: Photosynthetic reactions are divided into two phases:
1). The light dependent reactions or light reactions occurs when plants are illuminated. The chlorophyll and other light absorbing pigments in plants absorb sunlight and the sunlight is used to split water molecule in a process known as photolysis of water. In this process, ATP and NADPH are produced.
In carbon fixation or carbon dioxide assimilation reactions, the ATP and NADPH produced in light dependent reactions are used to drive this stage. This is the second phase of photosynthesis. In this phase, carbon dioxide is incorporated into ribulose 1,5-bisphosphate in a cyclic pathway and the product of these reactions is triose phosphate sugar. The triose phosphate sugar serves as a precursor for the synthesis of glucose and starch.