The main way the energy processing organelles, mitochondira and chloroplasts, can be contrasted is in the way they produce useful chemical energy and what they use to do it, according to Florida International University. Mitochondria are found in both animals and plants, while only plants and algae have chloroplasts.
Mitochondria and chloroplasts both have two major membranes: protective outer membranes and inner membranes with functional molecules for processing energy. Mitochondria are the major producers of the main energy currency of cells, ATP. They create ATP by respiration, in which oxygen is used in chemical reactions with the molecules obtained from food to release energy. This energy is then bound into ATP molecules, which can be used by the cellular machinery to perform essential tasks.
Chloroplasts do not produce ATP for the cell as a whole, but instead use the energy from sunlight to create sugars from carbon dioxide and water. Chloroplasts do actually produce ATP using the energy from sunlight, but this is used within the chloroplast to create sugars rather than being sent out to the rest of the cell for general use. The process of using ATP derived from sunlight to create sugars is known as the Calvin Cycle.