The chloroplast is the organelle of photosynthesis. In many ways, the chloroplast resembles the the 
mitochondrion. 

Both are surrounded by a double membrane with an intermembrane space. 
Both have their own DNA . 
Both are involved in energy metabolism. 
Both have membrane reticulations filling their inner space to increase the surface area on which reactions 
with membrane-bound proteins can take place.  

The chloroplast has three membranes: inner, outer, and thylakoid . It has three compartments: stroma, thylakoid space, and inter-membrane space. These compartments and the membranes that separate them serve to isolate different aspects of photosynthesis. Dark reactions take place in the stroma. Light reactions take place on the thylakoid membranes.