Physics and engineering departments are building research programs in biological physics, but until now there has not been a synthesis of this dynamic field at the undergraduate level. Biological Physics focuses on new results in molecular motors, self-assembly, and single-molecule manipulation that have revolutionized the field in recent years, and integrates these topics with classical results. The text also provides foundational material for the emerging field of nanotechnology. The text is built around a self-contained core geared toward undergraduate students who have had one year of calculus-based physics. Additional "Track-2" sections contain more advanced material for senior physics majors and graduate students.