Energy

__**Photosynthesis :**__ Autotrophs use light energy so chemical reactions convert carbon dioxide and water into oxygen and carbohydrates (sugars and starches). Plants are the main autotrophs on land. Photosynthetic bacteria, such as cyanobacteria, are in tidal flats and salt marshes. Energy flows in a one way path. •Sun – Living Organisms – Heat – Atmosphere. Light energy from the sun is used for plants to sustain themselves and reproduce. The excess energy is available as biomass, providing herbivores as the first trohic level.



**//__Chemosynthesis:__//** Autotrophs that produce food in no sunlight. Autotrophs rely on the chemical bonds of inorganic molecules (hydrogen sulfide). These organisms use chemicals to produce carbohydrates. Bacteria also performs the process of chemosynthesis. . Autotrophs convert sunlight(or chemical) energy into organic molecules. Less than 1% of energy from the sun is converted into organic material. After a certain extent all material is lost back into the atmosphere as heat.