The process of photosynthesis is two-part. First, there are the light reactions, where light is converted into chemical energy (a reduced electron carrier and ATP). This occurs in the thylakoids (stacked membranes) of the chloroplasts. The ATP and electron carriers are then used in a second set of reactions, called the light-independent reactions. This also occurs in the chloroplasts, but in an area called the stroma. In this case, carbon dioxide gets used to produce sugars in a series of reactions called the Calvin Cycle, C4 photosynthesis, and crassulacean acid metabolism. You can look in any basic bio textbook to see how much "energy" or "sugar" is produced in each step of the process.
Photosynthetic organisms use energy from sunlight to synthesize their own fuels. They can convert harvested sunlight into chemical energy (including ATP) to then drive the synthesis of carbohydrates from carbon dioxide and water. When they synthesize the carbohydrates, oxygen gets released. Globally, more than 10 billion tons of carbon is "fixed" by plants every year - this means that carbon molecules are converted from being part of a simple gas (carbon dioxide) into more complex, reduced molecules (carbohydrates), making carbon available as food for non-photosynthesizers (and of course, providing oxygen). They use some of the carbohydrate for their own growth and reproduction. It is pretty remarkable when you think about it - have you been to Sequoia National Park or seen the redwoods along our northwest coast? Massive trees, right? Think about the fact that most of that mass is in the form of carbon that was pulled out of the air as carbon dioxide!
In plants, algae and cyanobacteria, sugars are produced by a subsequent sequence of light-independent reactions called the , but some bacteria use different mechanisms, such as the . In the Calvin cycle, atmospheric carbon dioxide is into already existing organic carbon compounds, such as (RuBP). Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then and removed to form further carbohydrates, such as .
While new energy solutions are being discovered, refined and brought further and further into the public light, something that does not get a lot of headlines is waste to