Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.

By the end of this section, you will be able to do the following:

Describe the functions proteins perform in the cell and in tissues
Discuss the relationship between amino acids and proteins
Explain the four levels of protein organization
Describe the ways in which protein shape and function are linked

In this scrollable interactive, the four levels of protein folding are explored in detail by exploring the structure of hemoglobin.

Understandable lessons about numerous aspects about the composition, function, and interactions of proteins. Each starts with an interactive quiz and links to a tutorial.