1. Energy Chapter 6 p. 119-128

2. Energy Is Everywhere All life on Earth depends on energy from the sun Sun’s energy is not rechargeable Living things convert energy to a usable form

3. Defining Energy Capacity to do work Capacity to bring movement against an opposing force Present although it can’t be seen or grasped

4. Forms of Energy Potential Stored energy Example: ball at rest

5. Forms of Energy Kinetic Energy in motion Example: ball rolling, falling off table

6. Thermodynamics Study of energy Originated when better steam engine needed Helped begin Industrial Revolution

7. Laws of Thermodynamics First Law Energy cannot be created or destroyed Energy can only be transformed Excess unused energy is released as heat

8. Laws of Thermodynamics Second Law Energy release results in greater disorder Atoms change from structured, organized arrangement to less- ordered to release energy

9. Why don’t we burn up? Laws of Thermodynamics state that disorder increases in the universe as energy is released in the form of heat. We don’t burn up because we can build up and store energy for life processes.

10. Types of Reactions Exergonic- breaking down reaction, reactants have more energy than products –Example: starches to individual sugars

11. Types of Reactions Endergonic- building-up reaction, products have more energy than reactants –Example: glucose to glycogen

12. Glucose to Glycogen

13. Coupled Reactions Endergonic and exergonic reactions work together Exergonic (energy-releasing) reactions power endergonic (energy-consuming) reactions

14. The Main Energy Molecule: ATP ATP = Adenosine Triphosphate

15. The Main Energy Molecule Three phosphates contain stored energy Energy is released as phosphates are broken off Energy used for reactions and cellular functions

16. ATP as Money

17. Why don’t these reactions take longer? Enzymes- proteins that speed up chemical reactions Extremely important because no living thing could functions without them Each enzyme is specific for a different function

18. How Enzymes Work

19. Metabolism Metabolism- the sum of all the chemical reactions in an organism Metabolic pathway- a set of steps controlled by enzymes to make a specific product Like an assembly line where every enzyme has a job to do before the next piece can be assembled

20. A Very Complicated Metabolic Pathway!

21. How do enzymes relate to energy? Enzymes decrease the amount of energy needed to allow a reaction to proceed, known as activation energy.

22. Enzymes at Work

23. How do enzymes relate to energy? Enzymes are catalysts, meaning that they are not changed during a reaction and can be reused.