Which of the following changes involves the breaking and formation of chemical bonds?

The correct choice focuses on bio-synthesis changes, which indeed involve the breaking and formation of chemical bonds. When biological entities, such as cells or organisms, synthesize biomolecules—like proteins, nucleic acids, and lipids—they undergo chemical reactions that create new substances while also breaking existing bonds in precursor molecules. This process is fundamental in cellular metabolism, where the body builds complex molecules from simpler ones through various stages of biochemical reactions that involve the reconfiguration of atoms and bonds.

In contrast, electrical changes generally pertain to the flow and transfer of electrons without any direct alteration of molecular bonds. Concentration changes usually refer to variations in the amount of a substance in a solution but do not imply any chemical reactions or bond alterations. Heat changes often indicate a transfer of energy that may influence reaction rates or equilibrium but do not describe the specific biochemical processes involving bond formation and cleavage. Thus, the emphasis on bio-synthesis captures the essence of how chemical bonds are transformed in living systems.