Proteins are organic compounds which are formed of amino acids that are linked together by peptides. They help the body in getting nitrogen, vitamins and sulfur. Proteins are three dimensional in their structure. Their structure can be categorized into four distinctive aspects - primary structure, secondary structure, quaternary structure and tertiary structure. As this subject is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts and applications of the subject. This book is meant for students who are looking for an elaborate reference text on protein chemistry.