Photosynthesis is about three times the current power consumption of human civilization. Photosynthetic organisms also convert around 100–115 billion tonnes (91-104 petagrams) of carbon into biomass per year. Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide and water using energy from light. However, not all organisms use carbon dioxide as a source of carbon atoms to carry out photosynthesis; photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon. In plants, algae, and cyanobacteria, photosynthesis releases oxygen. This is called "oxygenic photosynthesis" and is by far the most common
Photosynthesis At 1000 ppm CO in measuring air, both the C3 and C4 plants had similar leaf photosynthetic rates around 60 μmol CO·m·s indicating the suppression of photorespiration in C3 plants. There are three main factors affecting photosynthesis and several corollary factors. The three main are: Total photosynthesis is limited by a range of environmental factors. These include the amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of