2. Where does the energy come from that sustains all life? The Sun!! Well most of it anyway……

3.  In the process of photosynthesis, plants convert the energy of sunlight into the energy in the chemical bonds of carbohydrates-sugars and starches.

4.  For many years, people wondered how a few seedlings could develop into a large tree.  The mass of seedlings are only a few grams, where as the mass of a tree is several tons.  Dutch physician Jan Van Helmont devised an experiment.  He concluded that the mass grew from the water, because that was the only thing he had added to the pot.  This was just one of the things needed for photosynthesis to occur.

5.  Helmont did not realize that carbon dioxide in the air also plays a major role in the contribution of mass growth.  The carbon in carbon dioxide is what is used to make carbohydrates in photosynthesis.

6.  Later on, scientist Joseph Priestly performed an experiment that would give rise to why oxygen is released in photosynthesis, and why sunlight is needed for it to photosynthesize.  Priestly placed a candle in a jar along with a mint plant.  He then realized that the candle could only stay lit when the mint plan was present.  This would mean that the plant was releasing oxygen.

7.  Through experiments, it was realized that in the presence of light, plants transform carbon dioxide and water into carbohydrates and release oxygen.  Plants that are able to use a source of energy, such as sunlight, to provide food directly from simple inorganic molecules are known as autotrophs.  This is made possible through photosynthesis.