Making your own food
Organisms producing their own food for themselves is called autotrophic nutrition.
Making food takes energy. Autotrophic nutrition divides according to where that energy comes from — into two groups.
The energy comes from sunlight.
Example — most plants.
The energy comes from a chemical reaction.
Example — most bacteria.
No chlorophyll, no photoautotrophy
Light energy is captured with the help of chlorophyll, a special organic substance held inside the chloroplasts of plant cells. Without chlorophyll no amount of sunlight will produce food.
A common misreading
"All plants are photoautotrophic" is wrong. There are parasitic plants with no chlorophyll — the dodder (Cassytha), for one, takes its food from the host plant it winds around. It is therefore heterotrophic.
The next page follows the process by which a photoautotrophic plant makes its food.