adenosine triphosphate is like a tiny molecular spring

An example of an analogy used in popular science writing:

"Think of ATP [adenosine triphosphate] as a tiny molecular spring that becomes coiled when it receives free energy. That packet of energy can then be accessed on demand by the chemical equivalent of releasing the spring in the ATP.

… carbohydrate molecules … are also chemical springs."

Paul Sen (2022) Einstein's Fridge. The science of fire, ice and the universe. William Collins.

The reference to carbohydrate molecules being chemical springs is in itself a metaphor, but can be understood in terms of the more developed accounts of ATP.

Read about analogy in science

Read examples of scientific analogies

Many examples of science analogies are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.