Final answer:
The light-dependent reactions of photosynthesis convert sunlight into chemical energy, while the light-independent reactions, or Calvin cycle, convert carbon dioxide into carbohydrates.
Step-by-step explanation:
In photosynthesis, the conversion of sunlight into chemical energy occurs in the light-dependent reactions. Chlorophyll absorbs energy from sunlight and converts it into chemical energy with the help of water. This process releases oxygen as a byproduct. On the other hand, the light-independent reactions, also known as the Calvin cycle, use the chemical energy derived from the light-dependent reactions to convert carbon dioxide into carbohydrates.