Talk about chloroplast stroma.

Contain a complex system of membranes whose structure, organization and density differ depending on species cell types and physiology. Called lamella suspended in stroma. Stroma contains a variety of particles such as strach granules resulting from polymerization of glucose produced by photosynthesis and lipid droplets. There are several copies of circular DNA and its accessory molecules, (ribosomes may be free or attached to thylakoids, In addition there is Rubisco (ribulose biphosphate carboxylase) which is the most abundant enzyme on earth, which catalyze CO2 fixation necessary for glucose formation.