Photosynthesis is a process whereby plants, some bacteria and a few types of algae convert energy from sunlight into chemical energy and store it as sugar. The internal fuel that plants use for survival is created by photosynthesis. Plants require carbon dioxide, water and light energy to synthesize sugar.
Photosynthesis occurs mostly in the leaves of the plant, in the mesophyll where the chloroplasts are contained. Chloroplasts contain the green pigment chlorophyll, which is essential to photosynthesis. Carbon dioxide enters the plant’s leaves through small openings known as stomata. The oxygen created during photosynthesis leaves through these same holes.
Photosynthesis takes place in two parts, according to an article on the University of Cincinnati -- Clermont College Biology website. The first part takes place in the light and is known as the “light reaction.” During this part, light energy is turned into chemical energy. The second part is known as the “dark reaction” in which carbon dioxide is converted to sugar.
Sugar and Oxygen
The chemical reaction that occurs during photosynthesis results in the production of sugar and oxygen. Humans and other animals need that oxygen to breathe, so the products of photosynthesis are essential to our survival. During photosynthesis, six molecules of water combine with six molecules of carbon dioxide to produce a single molecule of sugar and six molecules of oxygen.