In photosynthesis, energy from light reaction to dark reaction is...

As a result of light reaction, oxygen, NADPH and ATP are formed. Oxygen is released into the atmosphere while NADPH and ATP are utilised for reduction of $\mathrm{CO}_2$ to carbohydrate in dark reaction. Related Theory In the light reactions, light energy is converted into the chemical energy of ATP, while water is broken down for its hydrogen atoms. The ATP and hydrogen atoms are fed to the dark reaction which uses them to produce glucose sugar from carbon dioxide. Ultimately the light energy ends up in the glucose, but it does not get their easily. The light reaction trapped the solar energy and transferred it to the dark reaction via $A T P$ so that the dark reaction had the energy to make glucose. Essentially, the solar energy is being packaged into the chemical energy of glucose.