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:

Discuss the importance of electrons in the transfer of energy in living systems
Explain how ATP is used by cells as an energy source

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

Describe how electrons move through the electron transport chain and explain what happens to their energy levels during this process
Explain how a proton (H+) gradient is established and maintained by the electron transport chain

This 5-minute video lecture looks at oxidative phosphorylation and chemiosmosis (along with slight correction of previous video). [Biology playlist: Lesson 27 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Explains oxidative phosphorylation, which is the fourth step of cellular respiration, and produces the most of the energy in cellular respiration.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.