Now, the other type of molecule, the other type of organism that basically uses light as the energy source are known as phototrophs. So basically, plants are example of phototrophs because they use the energy stored and light to basically synthesize carbohydrate molecules. So they combine carbon dioxide, our inorganic carbon source, with water, and by using our light, they synthesize our carbohydrates as well as oxygen. So phototrophs are those organisms that use light as their energy source to power the different processes inside that organism. While chemo tropes obtain their energy by basically breaking down or oxidizing either inorganic or organic matter. In the case of humans, we basically oxidize our organic matter.