(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.
Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules (e.g., sugars). Photosynthesis powers almost all trophic chains and food webs on the Earth.
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).