Chloroplasts are the organelle that make plants green.The primary function of chloroplasts is photosynthesis, the light-driven fixation of carbon dioxide into organic compounds . The products of the photochemical reactions that occur within thylakoid membranes provide the material with which the plant cells grow and on which all forms of life on the surface of Earth depend.
Chloroplasts are one of the biggest organells. It has about fifty to one hundred flattend sacks called thylakoids. The word thylakoids comes from the greek meaning like an empty pouch