Photosynthetic biochemical reactions at night |

Cells often face low-oxygen conditions at night, when there's no photosynthesis releasing oxygen into the air and all photosynthetic and non-photosynthetic organisms in the environment are respiring oxygen. When this happens, some organisms such as the single-cell alga Chlamydomonas are able to generate cellular energy from the breakdown of sugars without taking up oxygen. Photosynthesis is probably the most well-known aspect of plant biochemistry. It enables plants, algae, and select bacteria to transform the energy from sunlight during the daytime into chemical energy in the form of sugars and starches (as well as oils and proteins), and it involves taking in carbon dioxide from the air and releasing oxygen derived from water molecules.  Read More: