2. Lecture 2 Outline (Ch. 8, 9) I.Energy and Metabolism II.Thermodynamics III.Metabolism and Chemical Reactions V.Cellular Energy - ATP VI.Enzymes & Regulation VII.Cell Respiration A.Redox Reactions B.Glycolysis C.Coenzyme Junction VII. Preparation for next Lecture

3. What is Energy? Energy Where does energy on earth come from originally? [equivalent of 40 million billion calories per second!]

4. Metabolism and Energy

5. Metabolism Metabolism –chemical conversions in an organism Types of Energy: - Kinetic Energy = energy of movement - thermal - Potential = stored energy- chemical

6. Potential energy can be converted to kinetic energy (& vice versa) Potential Energy Kinetic Energy Thermodynamics Thermodynamics – study of energy transformation in a system

7. Laws of Thermodynamics: Laws of Thermodynamics: Explain the characteristics of energy 1 st Law: Energy is conserved Energy is not created or destroyed Energy can be converted (Chemical  Heat) 2 nd Law: During conversions, amount of useful energy decreases No process is 100% efficient Thermodynamics Energy is converted from more ordered to less ordered forms Entropy (measure of disorder) is increased

8. Potential vs. Kinetic Energy

9. Metabolic reactions: All chemical reactions in organism Anabolic = builds up molecules Metabolism Two Types of Metabolic Reactions: Catabolic = breaks down molecules

10. Chemical Reaction: Process that makes and breaks chemical bonds + Reactants + Products Two Types of Chemical Reactions: 1) Exergonic = releases energy 2) Endergonic = requires energy Chemical Reactions

11. Metabolic reactions: Chemical reactions in organism Anabolic = build up Metabolism Two Types of Metabolic Reactions: Catabolic = break down Exergonic = release energy Endergonic = requires energy

12. Chemical Reactions Exergonic reaction Endergonic reaction -ΔG-ΔG release energy spontaneous +ΔG (or 0) intake energy non-spontaneous Glucose  CO 2 + H 2 0CO 2 + H 2 0  Glucose

13. Question/Recall: Which has more order? Stores more energy? Polymer or Monomer, Diffused or Concentrated H+? What is relationship between order and energy?

14. What type of energy is stored in a covalent bond? A.Kinetic energy B.Diffused energy C.Heat energy D.Potential energy E. Conventional energy

15. Cellular Energy - ATP ATP = adenosine triphosphate ribose, adenine, 3 phosphates last (terminal) phosphate - removable Be able to diagram ATP!

16. ATP hydrolyzed to ADP Exergonic ATP + H 2 OADP + P i Energy released, used in another reactions (endergonic) Cellular Energy - ATP

17. ATP regenerated cells power ATP generation by coupling to exergonic reactions Like cellular respiration! Cellular Energy - ATP

18. ATP Cycle

19. Making ATP from ADP + P i is… A.Exergonic because it releases energy B.Endergonic because it requires energy C.Exergonic because it requires energy D.Endergonic because it releases energy

20. Chemical Reactions: Like home offices – tend toward disorder Chemical Reactions

21. Chemical Reactions: Endergonic – energy taken in Exergonic – energy given off Exergonic Endergonic Chemical Reactions

22. Self-Check ReactionExergonic or Endergonic? Breaking down starches to sugars Building proteins Digesting Fats

23. Activation Energy: Energy required to “jumpstart” a chemical reaction Must overcome repulsion of molecules due to negative charged electrons Nucleus Repel Nucleus Repel Nucleus Activation Energy Activation Energy Chemical Reactions

24. Exergonic Reaction: –Reactants have more energy than products Activation energy: Make sugar and O 2 molecules collide Chemical Reactions “Downhill” reaction sugar + O 2 water + CO 2

25. Respiration (ch. 9) preview Cellular Respiration Equation: C 6 H 12 O 6 + O 2  CO 2 + H 2 O You will need to KNOW this equation.

26. Chemical Reactions and Enzymes Enzymes lower activation energy only for specific reactions cell chooses which reactions proceed! enzymes:cannot make rxns go that wouldn’t otherwise Do speed up rxns that would occur anyway Cannot change endergonic into exergonic rxns

27. Enzymes Enzymes – control rate of chemical reaction sucrase – enzyme sucrose breakdown sucrase – catalyst-speed up rxn, but not consumed “-ase” enzyme

28. Enzymes

29. enzyme – specific to substrate active site – part of enzyme -substrate binding tightens fit – induced fit form enzyme-substrate complex catalytic part of enzyme: converts reactant(s) to product(s)

30. Enzymes substrate(s) enter Enzymes lowers E A by: product(s) formed -template orientation -stress bonds -microenvironment enzyme reused What factors might affect enzyme activity?

31. Enzymes inhibitors: Drug – blocks HIV enzyme at the active site binds & blocks active site binds allosteric site – alters conformation

32. If a competitive inhibitor is in an enzyme reaction, can you reverse the inhibition by adding more substrate? A.Yes B.No C.I’m not sure D.Wait, what’s a competitive inhibitor?

34. Cellular Respiration Overall purpose: convert food to energy animals AND plants complementary to photosynthesis

35. Cellular Respiration: (Exergonic) Cellular Respiration catabolizes sugars to CO 2 requires O 2 at mitochondrion

36. Redox Reactions as part of chemical reaction, e- are transferred e- transfer = basis of REDOX reactions (reduction) (oxidation)

37. Redox Reactions follow the H, e- move with them Use “H rule” for reactions in this class Reactant with more H’s = e donor, will be oxidized Reactant with more O’s = e acceptor, will be reduced ZH 2 + O 2 yields ZO + H 2 O

38. Self-Check ReactionMolecule Reduced Molecule Oxidized ZH 2 + O 2 yields ZO + H 2 O CH 4 + 2O 2 yields CO 2 + 2H 2 O C 6 H 12 O 6 + O 2 yields CO 2 + H 2 O OxygenZH 2

39. Redox Reactions Equation for respiration

40. transfer of e- to oxygen is stepwise Redox Reactions

41. e- moved by NAD/H (from niacin/vit B 3 ) NADH  carry e- (reduced!) Where do e- come from? NAD+  not carrying e- (oxidized!) Where do e- go? glucose NADH ETC O 2 (makes H 2 O) Redox Reactions

42. In this equation is NAD+ to NADH oxidized or reduced? A.Reduced, it gained electrons B.Oxidized, it gained electrons C.Reduced, it lost electrons D.Oxidized, it lost electrons NAD + + H + + 2e-  NADH

43. 1. glycolysis - cytosol - mitochondrial matrix - inner mitochondrial membrane Steps of respiration : 2. Citric acid cycle 3. ETC 4. Chemiosmosis - inner membrane to intermembrane space Steps of Respiration Coenzyme Junction 4 CO 2 2 CO 2

44. Stages of respiration: 1. Glycolysis – prep carbons Cellular Respiration

45. 1. Glycolysis 1 glucose (6C)2 pyruvate (3C) Keep track of:- inputs - NAD+/NADH - ATP Cellular Respiration - CO 2 and H 2 O - outputs eukaryotes AND prokaryotes

46. ATP ADP 1 Glucose Glucose-6-phosphate Glycolysis 2 Glucose-6-phosphate Fructose-6-phosphate

47. Fructose- 1, 6-bisphosphate Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate 4 5 Glycolysis ATP ADP

48. 2 2 ADP 2 ATP Phosphoenolpyruvate 2 Pyruvate 10 Glycolysis 2 ATP 2 ADP

49. How many NET ATP are produced by glycolysis? A.one B.two C.four D.six E.eight

50. -inputs: CO 2 = none yet (2 H 2 O) -outputs: 1 Glucose 2 ATP 4 ATP (2 net) 2 NADH 2 pyruvate Where do the outputs go? Glycolysis Cellular Respiration

51. Energy production Mitochondria energy from nutrients  ATP

52. Coenzyme Junction 2 pyruvate (3C) 2 Acetyl CoA (2C) Cellular Respiration pyruvate joins coenzyme A (from vitamin B 5 ) 2 carbons lost (as CO 2 ) 2 NAD+  NADH

53. Things To Do After Lecture 2… Reading and Preparation: 1.Re-read today’s lecture, highlight all vocabulary you do not understand, and look up terms. 2.Ch. 8 Self-Quiz: #1-6 (correct answers in back of book) 3.Read chapter 9, focus on material covered in lecture (terms, concepts, and figures!) 4.Skim next lecture. “HOMEWORK” (NOT COLLECTED – but things to think about for studying): 1.Describe the relationship between exergonic/endergonic, catabolic/anabolic, and “uphill”/”downhill” chemical reactions 2.Diagram one molecule of ATP and how ADP is different 3.Cut apart the boxes on the previous sheet – match up three (name, energy balance, basic reaction) for glycolysis and three for the coenzyme junction 4.Place the following molecules in order for when they are used/created during glycolysis: fructose-6-phosphate, glucose, glucose-6-phosphate, pyruvate, glyceraldehyde-3-phosphate

54. Self-check at home