(mÄth'Än') A colorless, odorless, flammable gas that is the simplest hydrocarbon. It is the major constituent of natural gas and is released during the decomposition of plant or other organic compounds, as in marshes and coal mines. Methane is the first member of the alkane series.
In photosynthesis, solar energy is converted to chemical energy. The chemical energy is stored in the form of glucose (sugar). Carbon dioxide, water, and sunlight are used to produce glucose, oxygen, and water.
Photosynthesis converts these energy- depleted compounds (ADP and NADP+) back to the high energy forms (ATP and NADPH) and the energy thus produced in this chemical form is utilized to drive the chemical reactions necessary for synthesis of sugars and other carbon containing compounds (e.g., proteins, fats).