They are nature’s nanomachines. Proteins are the molecules in the body that it uses to get everything done. They act as catalysts to speed up chemical bonds that might take a billion years through other types of biological machinery. So whenever something needs to get done in biology, odds are, proteins are at work. They all have different functions, some are like scissors, some bring bonds together. They participate in virtually ever process within your body. If you think about the use of building nanomachines today, biology solved this millions of years ago. It amazes how well this works in the body.
Proteins are essentially sequences of amino acids, and they start off resembling a long stretched-out ribbon. Before they can do any work, they need to fold up into a functional three-dimensional shape. This shape largely determines what the protein can do in the body. Remarkably, proteins often spontaneously fold themselves! However, this process of protein folding, while critical and fundamental to virtually all of biology, remains a mystery.