The chloroplast is the site of photosynthesis in plants. It is surrounded by two membranes. The area between the inner and the outer membrane is the intermembrane space.
The fluid inside the inner membrane space is known as the stroma, and it contains 50% of the proteins of the chloroplast.
In the stroma there is a network of stacked discs known as thylakoids. Stacks of these discs are called grana. Thylakoids are the site of photosynthesis.
The membrane of the thylakoid contains chlorophyll, which converts sunlight into energy for photosynthesis.
The sugars produced by photosynthesis are stored as starch grains in the chloroplast.