1. Energy and Metabolism KEY WORDS: Energy Free Energy (ΔG) Potential energy Kinetic energy Enzyme Substrate Activation energy Exergonic reaction Endergonic reaction Catalyst ATP/ ADP

2. Energy The capacity to do work Move matter

3. Types of energy Question: __________ is an example of kinetic energy, and __________ is an example of potential energy. 1.Fire; a piece of wood 2.A loaded gun; a flying bullet 3.A rock on top of a hill; a rock rolling down the hill 4.None of these are correct. 5.All of these are correct. Kinetic Potential

4. Chemical Energy Stored in chemical bonds -high energy electrons Some molecules store a lot of energy Some molecules store much less Carbos, lipids Carbon dioxide, water

5. Chemical Energy Energy can be transferred/transformed Sugar + oxygen  carbon dioxide + water + heat C 6 H 12 O 6 + O 2  CO 2 + H 2 O + Energy

6. First Law of Thermodynamics: Energy: neither created nor destroyed Converted from one form to another Exchanged between substances

7. All exchanges of energy increase the entropy of the universe Entropy: Disorder or randomness of a system Heat is most disorganized form of energy Reactions that ↑ entropy happen spontaneously & release energy Second Law of Thermodynamics:

8. Two laws of thermodynamics

9. Energy Transformed

10. Exergonic Reactions Release energy “Spontaneous” Usually breakdown of complex molecules

11. Endergonic Reactions Not “Spontaneous” Usually involve synthesis of complex molecules 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Require energy + Energy

12. 1.CO 2 and H 2 O Glucose 2.Amino acids Proteins 3.TriglyceridesFatty acids 4.Ions moving across membrane from an area of high concentration to an area of low concentration. Question: Which of the following reactions is endergonic?

13. Question: Which of the following reactions releases energy? 1.CO 2 and H 2 O Glucose 2.Amino acids Proteins 3.TriglyceridesFatty acids 4.Ions moving across membrane from an area of high concentration to an area of low concentration.

14. Coupled Reactions glucose CO 2 + H 2 O Energy Exergonic Endergonic Energy Amino acids Protein Exergonic provides energy for the endergonic

15. Living organisms Metabolism All chemical reactions in an organism Anabolism Catabolism

16. Living organisms Capture energy to drive chemical reactions. Energy Energy Convert “raw” energy into usable form Sunlight, food ATP

17. The structure and hydrolysis of ATP

18. ATP: the Cell’s Rechargeable Battery ATP energy ADP charged batterydead battery This energy can then be used to run an energy requiring reaction.

19. The ATP cycle

20. 1.is never lost or gained, but is only transformed 2.always requires an ultimate source such as the sun 3.can never be gained, but can be lost 4.can never really be harnessed 5.can never be transformed According to the first law of thermodynamics, energy

21. 1.Some energy is lost, but other energy is created. 2.Some energy must come from the sun. 3.Some energy is transformed into heat. 4.Energy is gained for future use. 5.Some energy is permanently and completely destroyed. Each time there is a chemical reaction, some energy is exchanged. According to the second law of thermodynamics, with each exchange

22. 1.mechanical energy 2.heat 3.complex carbohydrates 4.chemical bond energy 5.amino acids ATP stores energy in the form of

23. The complexity of metabolism

24. Equation: Gibb’s Free Energy ΔG = ΔH – TΔS Energy available for work All energy Energy NOT available for work

25. The relationship of free energy to stability, work capacity, and spontaneous change

26. Energy changes in exergonic and endergonic reactions

27. Energy profile of an exergonic reaction

28. Disequilibrium and work in closed and open systems

29. Is ΔG for an exergonic reaction positive or negative?

30. What is the difference between: Anabolism Catabolism Metabolism

31. From an energy perspective, when is equilibrium reached?

32. Enzymes KEY WORDS: Enzyme Activation energy Catalyst Substrate Active site Induced fit Coenzyme Allosteric site Competitive inhibitor Noncompetitive inhibitor Feedback inhibition

33. Enzymes and Shape Active Site Induced fit: “Handshake” between substrate and enzyme

34. Activation Energy Net Energy Released

35. Enzymes Proteins that speed up chemical reactions (catalysts) Lower activation energy for a reaction

36. S = Substrates (reactants) enter reaction. P = Product (what you get at the end) result E = Enzymes mediate specific steps sucrase sucrose + H 2 O glucose + fructose E + S ES E + P Enzyme reactions can be simplified as:

37. The catalytic cycle of an enzyme

38. Enzymes Key Points: Catalyze reactions Don’t change reactions Same net release/use of energy Enzymes are not changed by reaction Each enzyme catalyzes a specific chemical reaction

39. Enzymes lower the barrier of activation energy

40. 1.lowering the temperature 2.lowering the pressure 3.using an enzyme 4.changing the amount of the reactants 5.supplying ATP Which of the following will lower the activation energy of a reaction in a cell?

41. 1.lowering the temperature 2.lowering the pressure 3.using an enzyme 4.changing the amount of the reactants 5.supplying ATP Which of the following will lower the activation energy of a reaction in a cell?

42. 1.accelerate specific chemical reactions 2.are not chemically altered by binding with a substrate 3.lower the activation energy of specific chemical reactions 4.all of the above 5.a and c only Enzymes

43. 4 Things that Affect Enzyme Activity 1.Substrate concentration 2.Enzyme concentration 3.pH 4.Temperature Shape of enzyme (Protein denatured)

44. Environmental factors affecting enzyme activity

45. Enzyme Regulation Enzymes can be turned on and off Regulated by other molecules in the cell Examples: –Allosteric regulation –Feedback inhibition –Inhibitors

46. Inhibition of enzyme activity

47. Allosteric regulation of enzyme activity

48. Feedback inhibition

49. If an enzyme solution is saturated with substrate, the most effective way to obtain an even faster yield of products is: a)Add more enzyme b)Heat the solution c)Add more substrate d)Add an allosteric inhibitor e)Add a noncompetitive inhibitor

50. An enzyme accelerates a metabolic reaction by a)Altering the overall free energy change for the reaction b)Making an endergonic reaction occur spontaneously c)Lowering the activation energy d)Pushing the reaction away from equilibrium e)Making the substrate molecule more stable

51. Some bacteria are metabolically active in hot springs because a)They are able to maintain a cooler internal temperature b)High temperature facilitates active metabolism w/o need of catalysis c)Enzymes have high optimal temperatures d)Enzymes are insensitive to temperature

52. 1.consists of a series of chemical reactions 2.uses a number of enzymes 3.involves the modification of a series of substrates 4.proceeds by means of each enzyme leaving a succeeding reaction to a different enzyme 5.all of the above Glycolysis is a metabolic pathway that helps living things extract energy from food. From this we know that glycolysis