Detailed explanation of the processes by which energy flows through an ecosystem. Scroll down and open Section 3.

Background information on the history of photosynthesis. An explanation for how light is used to assist in making food for plants as the transfer of electrons allows energy to flow through the system.

Heat flow from a hot region to a cold region is described and explained. Applications of this phenomenon (specifically heat pumps and refrigerators) are discussed. Excellent graphics.