Final answer:
The fundamental building block of energy in living organisms is the ATP molecule, which plays a key role in storing and transferring energy. Chemistry explores the transformation and transfer of energy in various forms and through chemical reactions.
Step-by-step explanation:
The fundamental building block of energy for organisms is a molecule known as ATP (adenosine triphosphate), which stores energy long-term in its chemical bonds and is used short-term to perform work. In broader terms, energy is generally the ability to do work and comes in various forms, including kinetic, potential, thermal, electrical, chemical, and nuclear.
The study of chemistry includes understanding how energy is transferred and transformed during chemical reactions, such as the combustion of gasoline to move a car, or the metabolic reactions in the body that break down food to release energy.