  This is a set of lectures that I presented at the Les Houches 2014 Summer
School "Topological Aspects in Condensed Matter Physics". The lectures are an
introduction to physics of proteins. To physicists, and by a physicist. My
lectures at les Houches were also celebration of the anniversary of
Schroedinger's 1944 lectures, and for that reason I decided to share my title
with his book.
