1 A cell gains energy by combining glucose with oxygen in a series of chemical reactions. The products are carbon dioxide and water. What is the source of this energy?

A. the forces that attract protons and neutrons within carbon nuclei

B. the breaking of chemical bonds within the molecules of the reactants

C. the breaking of chemical bonds within the molecules of the products

D. the kinetic energy of oxygen molecules

E. strong forces within the atomic nuclei of the reactants