Bioenergetics

1. Bioenergetics

2. Graphing Tuesday • Create a line graph with 2 y axes. • These are fake numbers @ hunting in Summer Shade!

3. Stem Cell Review • 1. What is a stem cell? _____________ ________ • 2. List the 2 types of stem cell: ______ ________ • 3. Which stem cell is controversial? Why? • 4. Where do they get adult stem cells from?

4. Review • Potential vs. Kinetic Energy • List 4 macromolecule types • How are these made/destroyed? • Functions of Each Macromolecule.

5. Metabolism • The sum of all chemical reactions occurring in an organism. • Catabolism- breaking down. EXERGONIC. Releases stored potential energy/heat. • Anabolism- building up. ENDERGONIC. Absorbs energy/heat from environment. • Anabolism and Catabolism are an example of ENERGY COUPLING…2 different processes united by common energy.

6. Energy (E) • Kinetic- energy of movement, usually e- or protons in Biology. • Potential- energy of position, usually in the chemical bonds of e-/p in Biology. • Cell Respiration releases energy (KE), Photosynthesis allows capture of E from great E source (PE)

7. Potential Energy vs. Kinetic Energy

8. Thermodynamics • Study of heat and its properties. • First Law of Thermodynamics: energy cannot be created/destroyed just transformed/transferred. • Second Law of Thermodynamics: every energy transfer increases entropy (disorder). • Most organized at conception, as you move towards death you become more organized…evolution?

9. Thermodynamics

10. Sunlight is high quality E, Heat is low quality E LE 8-3 CO2 Heat Chemical energy H2O First law of thermodynamics Second law of thermodynamics

11. Gibbs “Free” Energy- ability to work (make ATP/GTP) • Δ G = ΔH – TΔ S • G- Gibbs “free” energy • H – Enthalpy (Total usable energy in the system) • T – Temperature in Kelvin (273 + C⁰) • S- Entropy (Disorder created by something being broken down) • Δ – Change in a variable over time

12. Unstable (Capable of work)=LIVINGvs.Stable (no work)=DEAD G < 0 G = 0 A closed hydroelectric system

13. Catabolism if G is negative, e.g. cell respiration. There is free energy to do work Reactants Amount of energy released (G < 0) Final-initial E LE 8-6a Energy Free energy Products Progress of the reaction Exergonic reaction: energy released

14. Anabolism if G is positive, then it cannot do work, energy is bound up (photosynthesis=endergonic) Products LE 8-6b Amount of energy required (G > 0) Free energy Energy Reactants Progress of the reaction Endergonic reaction: energy required

15. Remember • Not all energy can be used… • Lots is lost to heat, some to waste (defacation)

16. P i P Protein moved Motor protein Mechanical work: ATP phosphorylates motor proteins Types of work performed by living cells Membrane protein ADP ATP + P i P P i Solute transported Solute Transport work: ATP phosphorylates transport proteins P NH2 NH3 P + + Glu i Glu Reactants: Glutamic acid and ammonia Product (glutamine) made Chemical work: ATP phosphorylates key reactants

17. ATP

18. ATP • The 3 PO4 make it very unstable. This instability allows it to do lots of work.

19. Phosphorylation Exergonic, can do work Endergonic, can’t do work ATPADP +Pi G=-13J ADP +Pi ATP G=13J

20. Phosphorus Cycle Initially in rocks, rocks weather, P then in soil or inwater to be used by producers to make phospholipids, DNA/RNA, proteins.

21. U2,D1 Data Set 1 Picture

22. Enzyme Review • Protein function is caused by structure…sequence of _ _ and how they are _. • All major processes in cells involve proteins. • Suffix of most proteins:_ • Proteins are catalysts: speed up and control rate of reactions.

24. Enzyme Review • Enzymes are not consumed in the reaction. Benefit? • Enzymes used to be described as “lock and key” now they are said to be “induced fit” or “fits like a glove” • H bonds responsible for induced fit

25. Enzymes Lower EA • Energy of Activation is the energy required to get the molecules lined up and ready for a reaction to take place (metabolism). • Because the molecules are sitting in the enzyme in position, it reduces all the time and energy of them “naturally” coming together. • Enzymes also eliminate the need for heat to move the molecules faster…we won’t incinerate ourselves during metabolism 

26. Course of reaction without enzyme EA without enzyme EA with enzyme is lower . Reactants Free energy Course of reaction with enzyme DG is unaffected by enzyme Products Progress of the reaction

27. Substrate . Active site Enzyme-substrate complex Enzyme

28. Enzymatic Process • Active Site- location of chemical reactions between enzyme and substrate. • Enzyme Substrate Complex- caused by induced fit. Held together by H bonds, ionic bonds, and Van der Waals. • The amino acid R groups perform the reaction.

29. R groups of Amino Acids

30. Substrates enter active site; enzyme changes shape so its active site embraces the substrates (induced fit). Substrates held in active site by weak interactions, such as hydrogen bonds and ionic bonds. • Active site (and R groups of • its amino acids) can lower EA • and speed up a reaction by • acting as a template for • substrate orientation, • stressing the substrates • and stabilizing the • transition state, • providing a favorable • microenvironment, • participating directly in the • catalytic reaction. . Substrates Enzyme-substrate complex Active site is available for two new substrate molecules. Enzyme Products are released. Substrates are converted into products. Products

31. 3 Factors that Affect Enzymes • 1. Temperature • 2. Salinity • 3.pH • *They all affect the 2*structure of proteins by altering the H bonds. • If a protein unwinds it is said to be __ • Type of protein that prevents misfolding_

32. Enzyme Inhibitors • These will slow or stop the rate of reactions • 1. Competitive Inhibitors- compete with substrate for active site, bind to active site, and SLOW reactions down. • 2. Non-competitive Inhibitors- bind somewhere to the enzyme, change the active site completely, and STOP reactions. • Inhibitors can be classified as reversible (Antabuse) or irreversible (Sarin-nerve gas)

33. A substrate can bind normally to the active site of an enzyme. Substrate Active site . Enzyme Normal binding A competitive inhibitor mimics the substrate, competing for the active site. Competitive inhibitor Competitive inhibition A noncompetitive inhibitor binds to the enzyme away from the active site, altering the conformation of the enzyme so that its active site no longer functions. Noncompetitive inhibitor Noncompetitive inhibition

34. Allosteric Enzymes “Allo” different, “stery” shape • Enzymes that will change shape, thus being turned off or on. • Inhibitor molecules turn the enzyme off • Feedback Inhibition or Negative Feedback Loop-prevents wasting energy • Activator molecules turn the enzyme on

35. Initial substrate (threonine) Active site available Threonine in active site Enzyme 1 (threonine deaminase) Isoleucine used up by cell Feedback Inhibition or Negative Feedback Intermediate A Feedback inhibition Enzyme 2 Active site of enzyme 1 can’t bind theonine pathway off Intermediate B Enzyme 3 Intermediate C Isoleucine binds to allosteric site Enzyme 4 Intermediate D Enzyme 5 End product (isoleucine)

36. Cooperativity • One active site helps other active sites on the same molecule. • RBC-4 part molecule, each part carries O. When Part 1 fills with O the next part does …and RBC deliveer O in the same way. • This is an example of cell efficiency/specializatino, conservation of E, and regulation.

37. Polypeptide chain b Chains Proteins involved in constructing a red blood cellQuaternaryStructure Iron Heme a Chains Hemoglobin Polypeptide chain Collagen

38. Bioenergetics • Enzymes are needed in all efficient energy reactions. • Two energy reactions we will focus on: • Photosynthesis- anabolic, endergonic, +G • Cell Respiration-catabolic, exergonic, -G

39. Remember • Electrons are a source of E • CHOs come from H20 and CO2 by plant’s chloroplast • E in a molecule is directly related to # H present. • Autotrophs = • Heterotrophs =

40. Autotroph - Plants

41. Autotroph - Algae

42. Autotroph - Phytoplankton

43. Autotroph - Bacteria

44. Heterotroph - Animal

45. Heterotroph - Fungus

46. Photosynthesis • Chlorophyll- light absorbing protein pigment that reflects green light. Found in plants, algae, and blue-green bacteria. • Chloroplast- organelle that contains grana (thylakoids) and stroma

47. Chloroplast

48. Chloroplast Parts • Thylakoids- contain chlorophyll. Site of Light reaction. Purpose is to make ATP & NADPH. • Grana- stacks of thylakoids • Stroma- watery area @ thylakoids. Site of light independent (Calvin Cycle). Purpose is to use ATP & NADPH to make glucose using CO2

49. Photosynthesis chemical reaction(Remember… conservation of matter.) • 6 CO2 + 6 H2O  C6H12O6 + 6 O2 + Heat

50. Photosynthesis • Take radiant energy and convert into chemical energy (ATP & NADPH) • Take chemical energy (ATP & NADPH) and turn it into potential chemical energy (carbohydrate). Sugar creation is done by catabolism.