Metabolism and Energy

1. MetabolismandEnergy Chapters 8

2. Metabolism and Energy Organisms are energy transformers! • Metabolism • Catabolism • Anabolism • Bioenergetics • Energy • Kinetic • Heat/Thermal • Light Energy • Potential • Chemical

3. Metabolism and Energy Organisms are energy transformers! • Metabolism • Metabolic pathway begins with a specific molecule, which is then altered in a series of defined steps leading to a specific product • Each step is catalyzed by a specific enzyme

4. Metabolism and Energy Organisms are energy transformers! • Metabolism • Catabolism • Energy released (helps to drive anabolic pathways). • Ex: cellular respiration • sugar put in to the body is broken down to do work in the cell (movement, active transport, etc).

5. Metabolism and Energy Organisms are energy transformers! • Metabolism • Catabolism • Anabolism • sometimes called biosynthetic pathways- • Ex: synthesis of a protein from amino acids. • Energy required/absorbed.

6. Metabolism and Energy Organisms are energy transformers! • Metabolism • Catabolism • Anabolism • Bioenergetics • the study of how energy flows through living systems.

7. Metabolism and Energy Organisms are energy transformers! • Metabolism • Catabolism • Anabolism • Bioenergetics • Energy • the capacity to cause change. • Some forms of energy can be used to do work- or move matter against opposing forces • Ex: (friction and gravity) • Ability to rearrange a collection of matter

8. Metabolism and Energy Organisms are energy transformers! • Energy • Kinetic • Relative motion of objects • moving objects can perform work by imparting motion to other matter. • Ex: Moving water through a dam turns turbines, moving bowling ball knocks over pins

9. Metabolism and Energy Organisms are energy transformers! • Energy • Kinetic • Heat/Thermal • comes from the movement of atoms or molecules associated with kinetic energy

10. Metabolism and Energy Organisms are energy transformers! • Energy • Kinetic • Heat/Thermal • Light Energy Type of energy that can be harnessed to perform work Ex. Powering Photosynthesis

11. Metabolism and Energy Organisms are energy transformers! • Kinetic • Heat/Thermal • Light Energy • Potential • Non-kinetic energy • because of location or structure, height, chemical bonds, etc.

12. Metabolism and Energy Organisms are energy transformers! • Kinetic • Heat/Thermal • Light Energy • Potential • Chemical • the potential energy available for release by a reaction. • Ex: Glucose is high in chemical energy and the process of glycolysis breaks it down. As bonds are broken, energy is released, but bonds also reform to make new molecules, thus it uses some energy.

13. Metabolism and Energy Organisms are energy transformers! All original energy comes from light. (photosynthesis- primary producer- consumer- who changes it from chemical to kinetic and releases thermal.

14. Thermodynamics • What is Thermodynamics?

15. Thermodynamics • The energy transformations that occur in a collection of matter

16. Thermodynamics • Thermodynamics • System vs. Surroundings • Isolated System vs. Open System • First Law of Thermodynamics

17. Thermodynamics • Two Laws of Thermodynamics govern energy exchange: • First Law of Thermodynamics • Second Law of Thermodynamics

18. Thermodynamics • Two Laws of Thermodynamics govern energy exchange: • First Law of Thermodynamics • energy cannot be created or destroy- • Only transferred or transformed • Known as Principle of conservation of energy

19. Thermodynamics • Second Law of Thermodynamics • During energy transfer, some energy become unusable energy (unavailable to do work) • Entropy (S) – Measure of disorder or randomness

20. Thermodynamics • So, What is the Second Law of Thermodynamics? • Every energy transfer or transformation increases the entropy of the universe

21. Thermodynamics • Spontaneous (Energetically Favorable) vs. Nonspontaneous Processes • Leads to the second way we state the 2nd Law of Thermodynamics: • For a process to occur spontaneously, it must increase the entropy of the universe

22. Think-Pair-Share • How does the second law of thermodynamics help explain the diffusion of a substance across a membrane? • If you place a teaspoon of sugar in the bottom of a glass of water, it will dissolve completely over time. Left longer, eventually the water will disappear and the sugar crystals will reappear. Explain these observations in terms of entropy.

23. Gibbs Free Energy • Free Energy • Portion of system’s energy that can perform work when temp and pressure are uniform throughout system • ΔG = free energy of a system • -ΔG = spontaneous reaction • +ΔG = nonspontaneous reaction • ΔG = 0 = Dead Cell (can do no work) ΔG = ΔH – TΔS ΔG = ΔGfinal – ΔGinitial • Enthalpy

24. Gibbs Free Energy ΔG = ΔH – TΔS ΔG = ΔGfinal – ΔGinitial • ΔH = he change in the system’s enthalpy • What is enthalpy? • Total energy • ΔS = change in system’s entropy • T = absolute Temperature in Kelvin

25. Gibbs Free Energy ΔG = ΔH – TΔS ΔG = ΔGfinal – ΔGinitial • Can think of this as difference in final state and initial state

26. Gibbs Free Energy • Endergonic vs. Exergonic Reactions +ΔG -ΔG Non-Spontaneous Spontaneous

27. Gibbs Free Energy • Reactions in isolates system eventually reach equilibrium and then cannot do work • Metabolism reactions are reversible and eventually will reach equilibrium • Living cell is not in equilibrium • Some reactions are constantly pulled in one direction and this keeps them from reaching equilibrium

28. Warm Up Exercise • Glow in the dark necklaces are snapped in a way that allows two chemicals to mix and they glow. Is this an endergonic or exergonic reaction? Explain. • In simple diffusion, H+ ions move to an equal concentration on both sides of a cell membrane. In cotransport, H+ ions are pumped across a membrane to create a concentration gradient. Which situation allows the H+ ions to perform work in the system?

29. ATP and Cellular Work • Three Types of Work • Chemical • Transport • Mechanical • Energy Coupling • Phosphorylated Intermediate

30. Why is ATP such a good energy molecule? • What is ATP? • Contains ribose sugar, nitrogenous base adenine, and chain of 3 phosphate groups bonded to it. • Bonds can be broken by hydrolysis

31. Why is ATP such a good energy molecule? • When bond is broken , a molecule of inorganic phosphate leaves the ATP • It become adenosine diphosphate (ADP)

32. Is Hydrolysis of ATP endergonic and exergonic? Anabolic or catabolic?

33. Does it release -7.3 kcal / mol in the cell?

34. ATP Hydrolysis • kh

35. ATP and Cellular Work

36. ATP Cycle • The body regenerates 10 million molecules of ATP per second per cell!

37. Enzymes • Enzymes- biological catalyst • Substrates – reactants that bind to the enzyme, usually in the active site

38. Enzymes • Activation Energy (EA) • the energy required to get a reaction started. • Many times this energy is absorbed as thermal energy from the environment • Many times room temperature may be enough, but most reactants need more energy than that to get started. AKA = free energy of activation

39. Enzymes • Activation Energy (EA) • the energy required to get a reaction started.

40. How does heat effect an enzyme? • Heat speeds a reaction by allowing reactants to attain the transition state more often • This solution is inappropriate for biological systems because it would denature proteins and kill cells. • Additionally, it would speed up all reactions, not just those that are needed.

41. Enzymes • Enzymes catalyze reactions by lowering the activation energy.

42. Enzymes • Enzyme + Substrate = Enzyme-Substrate Complex Enzyme Enzyme- Enzyme + Substrate + Substrate(s) Complex Product(s)

43. Enzymes • Active Site • pocket or groove on the surface of the enzyme where the substrate binds and catalysis occurs.

44. Enzymes • Induced Fit • When the substrate enters the active site, it forms weak bonds with the enzyme, inducing a change in the shape of the protein. This change allows additional weak bond (ie: hydrogen bonds) to form, causing the active site to fit around the substrate snugly-

45. Effects of Environment • Changes in the environment of the enzyme can cause inefficiencies or denaturation of the enzyme: • Temperature • pH • Concentration of Enzyme • Concentration of Substrate

46. Enzymes • Cofactors • nonprotein components that help in catalytic activity. • Usually bound to enzyme (sometimes permanently, sometimes loosely) • Coenzyme • If cofactor is organic • Many vitamins are important because they are coenzymes or make up coenzymes

47. Enzyme Action • Competitive Inhibitors • Resembles normal substrate molecule • Reduce productivity of enzyme by blocking substrates from entering active sites

48. Enzyme Action • Noncompetitive Inhibitors • Don’t directly compete with substrate • Impede enzymatic reactions by binding to another part of the enzyme

49. Allosteric Regulation

50. Allosteric Regulation • Term used to describe any case in which a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site • Can be inhibition or stimulation • Generally constructed from two or more subunits