Chloroplasts are made up of the macromolecules- phospholipids, protein, and nucleic acids.
Chloroplasts are the food producers of the cell. The organelles are only found in plant cells and some protists such as algae. Animal cells do not have chloroplasts.
Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells. The entire process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast.
In the process of photosynthesis, plants create sugars and release oxygen (O2). The oxygen released by the chloroplasts is the same oxygen you breathe every day. Mitochondria work in the opposite direction. They use oxygen in the process of releasing chemical energy from sugars.
To learn more about the Cell Structure of Chloroplasts, see Biology4Kids.com.