If we look into how energy is produced by the humans, it always involves some kind of periodicity: fuel combustion rotates engines, water rotates turbines, nuclear chain reactions heat up water, which rotates turbines, dynamo machines, etc.
So that means that with a few exceptions humans produce most energy (electricity) using rotation or some kind of cyclical rotative movement (as it proved to be the most efficient way of doing that).
Now what if we look at the human body? It is producing the energy from the food that we consume, converting carbs and proteins into glucose, which is then broken down into carbon dioxide, water and ATP. This ATP is then used in chemical reactions that are needed to contract the muscles or to send impulses within the brain.
The question is: Does anybody know – are those chemical reactions also cyclical in their nature? And if not, what's the common dynamical property (pattern) that can be observed in them all, if any?
Thank you and sorry for the long intro, but I thought it's important you know where I come from.