Plants are very important to all life forms on earth. They help provide the vital source of oxygen that is required to sustain life. But how do plants provide oxygen? What do they do with carbon dioxide? Animals not only get the benefits of oxygen from plants, they also get nutrients by eating them. Without plants, all life forms that require oxygen would be non-existent.
Plants release oxygen through a process called photosynthesis. Photosynthesis needs three things in order to start this process. They are carbon dioxide, water and sunlight. Carbon dioxide is taken from the atmosphere and then passes through the stomata and into the air spaces of the spongy mesophyll cells. During this process, plants use the energy from the sun to split the water molecules into hydrogen and oxygen. The oxygen molecules are given off by the plant and emitted into the atmosphere as a waste product. Molecules of Adenosine Triphosphate (ATP) and Nicotinamide Adenine Dinucleotide Phosphate (NADPH) are created within the plant cell. These reactions are called photochemical or light reactions because they require light to occur. The overall reaction of this entire process is six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen.
Enzymes within the plant then catalyze the combination of hydrogen and carbon dioxide to create a carbon compound that is called an intermediate. An intermediate is a compound used to continue a process to create a different compound. In plants, the intermediate is called phosphoglyceraldehyde (PGAL). PGAL goes on in the process to produce glucose, which the plant uses as fuel to survive. These reactions are called carbon-fixation reactions. When the plant has created more glucose than it needs to sustain life, it combines glucose molecules into larger carbohydrate molecules called starch. The starch molecules are stored within the large vacuoles in the plant cells....