1. Light-dependent reactions: This occurs in the thylakoid membranes of chloroplasts. Sunlight is absorbed by chlorophyll, which energizes electrons. This energy is used to create ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy carriers. Oxygen is also produced as a byproduct.

2. Light-independent reactions (Calvin cycle): This takes place in the stroma of chloroplasts. The energy from ATP and NADPH is used to convert carbon dioxide into glucose, a simple sugar. This is where the carbon fixation occurs.

So, to answer your question directly, it depends on which part you are referring to!