Proteins are pretty incredible

I guess this aligns with my recent post about card shuffling and the mind boggling mathematics of the number of possible outcomes.  

Proteins have the same feature.  From a Science magazine article, nominating AI work on working out protein structures as the breakthrough of 2021:

Proteins are biology’s workhorses. They contract our muscles, convert food into cellular energy, ferry oxygen in our blood, and fight microbial invaders. Yet despite their varied talents, all proteins start out with the same basic form: a linear chain of up to 20 different kinds of amino acids, strung together in a sequence encoded in our DNA. After being assembled in cellular factories called ribosomes, each chain folds into a unique, exquisitely complex 3D shape. Those shapes, which determine how proteins interact with other molecules, define their roles in the cell.

Work by Anfinsen and others suggested interactions between amino acids pull proteins into their final shapes. But given the sheer number of possible interactions between each individual link in the chain and all the others, even modest-size proteins could assume an astronomical number of possible shapes. In 1969, American molecular biologist Cyrus Levinthal calculated that it would take longer than the age of a universe for a protein chain to cycle through them one by one—even at a furious pace. But in nature, each protein reliably folds up into just one distinctive shape, usually in the blink of an eye.