This booklet reveals how structural biology provides insight into health and disease and is useful in developing new medications. It contains a general introduction to proteins, coverage of the techniques used to determine protein structures, and a chapter on structure-based drug design. The booklet features "Student Snapshots," designed to inspire young people to consider careers in biomedical research. Review questions at the end of each chapter are also included. Chapter 1 discusses the "structures of life" and their role in the structure and function of all living things. In Chapters 2 and 3, X-ray crystallography and nuclear magnetic resonance spectroscopy tools that structural biologists use to study the detailed shapes of proteins and other biological molecules are described. Chapter 4 explains how the shape of proteins can be used to help design new medications, in this case drugs to treat AIDS and arthritis. Chapter 5 provides more examples of how structural biology teaches about all life processes, including those of humans. (Contains a glossary.)