Chloroplasts are found in plants and some protist organisms. These organisms use green pigments called chlorophyll to convert light into energy through a series of chemical reactions.
A chloroplast is an organelle, a smaller part of a cell that has specialized functions. Similar to mitochondria in animal cells, chloroplasts contain their own DNA and reproduce separately from the cells that contain them. Because of their similarity to mitochondria and bacteria, scientists believe chloroplasts were once separate and managed to join with an organism's cells rather than be digested by an attacking cell. This integration formed a symbiotic relationship that allowed these life forms to thrive in the sun.