Autotrophic nutrition is a type of nutrition in which organisms are able to produce their own food using energy from external sources. This is in contrast to heterotrophic nutrition, in which organisms obtain food by consuming other organisms.
The most common form of autotrophic nutrition is photosynthesis, in which plants, algae and some bacteria use energy from the sun to convert carbon dioxide and water into glucose and oxygen. This process is carried out by chlorophyll, which is found in the chloroplasts of plant cells and in the chlorophyll-containing organelles of algae and some bacteria.
Another form of autotrophic nutrition is chemosynthesis, in which organisms use energy from chemical reactions to produce organic compounds. This process is found in some bacteria that live in environments such as deep sea hydrothermal vents and in the absence of light, these organisms use sulfur compounds as an energy source to produce organic compounds from inorganic ones.
In summary, autotrophic nutrition is a type of nutrition in which organisms use energy from external sources to produce their own food, usually in the form of organic compounds, and it can happen through photosynthesis or chemosynthesis.