It is a large, complex double membraned organelle that performs the function of photosynthesis within plant cells and contains the substance chlorophyll...
The chloroplasts use photosynthetic chlorophyll pigment and take in sunlight, water and carbon dioxide to produce glucose and oxygen.
An important structure in the chloroplasts is the inter-connected, flattened, membranous sacs called thylakoids.
These are the site of the photosynthetic light reactions and it involves the transfer of electrons.
The chloroplasts have their own DNA and ribosomes.