The book is intended for high school students. It examines in detail the structure of the protein, the main properties of protein molecules, the role of proteins in the body. Much attention is paid to biological catalysts - enzymes. Students will get acquainted with the basic methods of studying proteins, with their transformation in the body and the synthesis of artificial protein. The authors in presenting the material are based on the knowledge gained by students in chemistry and biology classes. Book for extracurricular reading of 10th grade students.