(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.
The hydrogen is provided by the NADPH, which is produced in the Light Rx and carried to the Dark Rx; the stored chemical energy as part of the glucose molecule is provided by the ATP (from the Light Rx). The overall photosynthesis process, from start to finish is summarized in the text on page 116 and in Figure 7.10.