CHLOROPLASTS: Is where photosynthesis occurs, which makes food or the plant, They contain a green substance called chlorophyll which absorb light.
Chloroplasts are surrounded by a double membrane and also have membranes inside called thylakoid membranes. These are stacked up in the chloroplast to from grana.
Grana are linked together to by lamellae (thin flat pieces of thylakoid membranes). Some photosyntheisis happens in the grana and others in the stroma (thick fluid found in chloroplasts).