Site of the light-dependent reaction

Chloroplasts are structurally adapted to their function of capturing sunlight and carrying out the light-dependent reaction in the following ways:

1. The thylakoid membrane provides a large surface area, which allows the attachment of chlorophyll, electron carriers, and enzymes that carry out the light dependent reaction e.g rubisco.

2. The network of proteins in the grana hold the chlorophyll in a specifc way to maximise the absorption of light

3. There are ATP synthase channels in the tylakoid membranes to form ATP. 

4. The thylakoid membranes are selectively permeable so a proton (H+) gradient can be established across the membrane.

5. Chloroplasts contain DNA and ribosomes so they can quickly and easily manufacture proteins involved in the light-dependent reaction.