1. Figure 6.1

2. Figure 6.UN01 Enzyme 1 Starting molecule Enzyme 2 Enzyme 3 Reaction 1 Reaction 2 Reaction 3 ProductDC B A

3. Figure 6.2 A diver has more potential energy on the platform. A diver has less potential energy in the water. Diving converts potential energy to kinetic energy. Climbing up converts the kinetic energy of muscle movement to potential energy.

4. Figure 6.3 (a) First law of thermodynamics (b) Second law of thermodynamics Chemical energy Heat

5. Figure 6.4

6. Figure 6.5 (a) Gravitational motion (c) Chemical reaction (b) Diffusion More free energy (higher G) Less stable Greater work capacity Less free energy (lower G) More stable Less work capacity In a spontaneous change The free energy of the system decreases (  G  0) The system becomes more stable The released free energy can be harnessed to do work

7. Figure 6.6a (a) Exergonic reaction: energy released, spontaneous Amount of energy released (  G  0) Reactants Products Energy Progress of the reaction Free energy

8. Figure 6.6b (b) Endergonic reaction: energy required, nonspontaneous Amount of energy required (  G  0) Reactants Products Energy Progress of the reaction Free energy

9. Figure 6.7a (a) An isolated hydroelectric system  G  0  G  0

10. Figure 6.7b  G  0 (b) An open hydroelectric system

11. Figure 6.7c  G  0 (c) A multistep open hydroelectric system

12. Figure 6.8a (a) The structure of ATP Phosphate groups Adenine Ribose

13. Figure 6.8b (b) The hydrolysis of ATP Energy Adenosine triphosphate (ATP) Adenosine diphosphate (ADP) Inorganic phosphate

14. Figure 6.7c  G  0 (c) A multistep open hydroelectric system

15. Figure 6.9a (a) Glutamic acid conversion to glutamine Glutamic acid  G Glu   3.4 kcal/mol Glutamine Ammonia

16. Figure 6.9b (b) Conversion reaction coupled with ATP hydrolysis Glutamic acid Glutamine Phosphorylated intermediate Phosphorylated intermediate

17. Figure 6.9c (c) Free-energy change for coupled reaction  G Glu   3.4 kcal/mol  G ATP  −7.3 kcal/mol  G Glu   3.4 kcal/mol  G ATP  −7.3 kcal/mol   G  −3.9 kcal/mol Net

18. Figure 6.11 Energy from catabolism (exergonic, energy- releasing processes) Energy for cellular work (endergonic, energy-consuming processes)