All reactions of photosynthesis that directly depend on light are known as the light reactions.

They occur in the the thylakoids (Stacks of thylakoids are known as grana.).

The purpose of the light reactions is to convert light energy into chemical energy in the form of ATP & NADPH.

ATP & NADPH are energy carriers. They carry energy to the 2nd part of photosynthesis, known as the dark reactions.

ATP carries only energy to the dark reactions.

NADPH carries energy & hydrogen to the dark reactions.

1. Light absorption & splitting of water (provides energy & Hydrogen to make sugar)

2. Movement of energized electrons through electron acceptors to make ATP

3. Re-energizing electrons so they can produce NADPH.

4. Energy carriers ATP & NADPH carry energy to the dark reactions (so sugar can be made).