Proteins are remarkable molecular machines: they digest your food, fire your neurons, power your immune system and so much more. What if we could design new ones, with functions never before seen in nature? In this remarkable glimpse of the future, David Baker shares how his team at the Institute for Protein Design is creating entirely new proteins from scratch -- and shows how they could help us tackle five massive challenges facing humanity. (This ambitious plan is a part of the Audacious Project, TED's initiative to inspire and fund global change.)