Adenosine-5'-triphosphate (ATP)
or perhaps glucose (a sugar).
glucose
Fried chicken. It is the quintessential source of energy. Ask my man Kevin Durant.
The type of molecule that serves as a living things main source of energy is a carbohydrate. The most important carbohydrate is glucose. Glucose is the basic form of fuel in living things.
Most living things use sugars as a source of energy. Energy can be stored as fats or sugars, and it can be transported as those molecules as well.
Last I heard, the energy molecule for humans is ATP, adenosine triphosphate. I don't think that other living things such as plants have ATP. They do photosynthesis. But regarding humans, ATP is taught to be the energy molecule.
bacteria? No. The chemical storage molecule for energy, in living things, is ATP, adenosine triphosphate.
glucose is the source of energy for all living things.
DNA
Many living things release energy from the sugar molecule glucose.
Glycogen
All living things require a source of energy.
sunlightThe sun is the main source of energy on planet Earth.