One of the most important concepts to discuss is that of photosynthesis. This amazing process powers every life form on the planet directly or indirectly. Photosynthesis occurs in the leaves where chloroplasts uses the energy of light to combine carbon dioxide and water to form carbohydrates. Carbohydrates are formed as digestible and indigestible form. Cellulose is indigestible and edible food products are digestible carbohydrates. See references
Photosynthesis song https://www.youtube.com/watch?v=wj8TGhcCnxs
https://sciencing.com/photosynthesis-place-5481899.html