1. CELLULAR RESPIRATION

2. CELLULAR ENERGY Energy In The Cell

3. ENERGY Life requires energy and cells are energy transformers Energy is the capacity to do work and the capacity to rearrange matter – Work is accomplished when an object is moved against an opposing force, such as friction – There are two kinds of energy –Kinetic energy - energy of motion –Potential energy - energy that an object possesses as a result of its location

4. METABOLISM Is the total of an organisms chemical reactions Metabolic pathway – a series of chemical reactions that either break down a complex molecule or build up a complex molecule Energy coupling – use of energy released from exergonic reactions to drive essential endergonic reactions

5. ATP – ADENOSINE TRIPHOSPHATE Is the energy currency of cells. ATP powers most forms of cellular work. It is composed of adenine (a nitrogenous base), ribose (a five- carbon sugar), and three phosphate groups. Triphosphate – all 3 phosphate groups are negatively charged. The charges repulse each other. – The bonds connecting the phosphate groups are unstable and can be broken by hydrolysis.

6. ATP – ADENOSINE TRIPHOSPHATE Hydrolysis of ATP releases energy by transferring its third phosphate from ATP to some other molecule – The transfer is called phosphorylation – In the process, ATP energizes molecules

8. Ribose Adenine Triphosphate (ATP) Adenosine Phosphate group Hydrolysis Diphosphate (ADP) Adenosine 

9. ATP – ADENOSINE TRIPHOSPHATE Cellular work – 3 main types – Chemical work—phosphorylation of reactants provides energy to drive the endergonic synthesis of products – Transport work—pumping substances across membranes – Mechanical work—is the transfer of phosphate groups to special motor proteins in muscle cells causing the proteins to change shape and pull on actin filaments causing contractions (beating of cilia)

10. Chemical work Solute transportedMolecule formed Product Reactants Motor protein Membrane protein Solute Transport workMechanical work Protein moved

11. ATP – ADENOSINE TRIPHOSPHATE ATP is a renewable source of energy for the cell – When energy is released in an exergonic reaction, such as breakdown of glucose, the energy is used in an endergonic reaction to generate ATP – A phosphate group is added to ADP to form ATP ATP VIDEO

12. Energy from exergonic reactions Energy for endergonic reactions

13. CELLULAR ENERGY Cellular Respiration

14. CELLULAR RESPIRATION Process that releases energy by breaking down glucose IN THE PRESENCE OF O 2. Happens in the mitochondria

15. Energy is necessary for life processes – These include growth, transport, manufacture, movement, reproduction, and others – Energy that supports life on Earth is captured from sun rays reaching Earth through plant, algae, protist, and bacterial photosynthesis – So ultimately the energy comes from the sun! PHOTOSYNTHESIS AND CELLULAR RESPIRATION

16. PHOTOSYNTHESIS - ENERGY IN SUNLIGHT IS USED IN PHOTOSYNTHESIS TO MAKE GLUCOSE FROM CO 2 AND H 2 O WITH RELEASE OF O 2 CELLULAR RESPIRATION - ORGANISMS USE THE O 2 AND ENERGY IN SUGAR AND RELEASE CO 2 AND H 2 O THESE TWO PROCESSES ARE RESPONSIBLE FOR THE MAJORITY OF LIFE ON EARTH ENERGY COUPLING VIDEO ENERGY COUPLING VIDEO ECOSYSTEM Photosynthesis in chloroplasts Glucose Cellular respiration in mitochondria H2OH2O CO 2 O2O2 (for cellular work) ATP Sunlight energy Heat energy

17. Breathing – exchange of gases Organisms obtain oxygen and release carbon dioxide as a waste product. Cellular respiration – the aerobic (with oxygen) harvesting of energy from food molecules When you breathe in air, oxygen is taken to your lungs where it can then enter your bloodstream. The blood carries oxygen to your cells. BREATHING AND CELLULAR RESPIRATION

18. The mitochondria in your cells use oxygen in cellular respiration to make energy (ATP) from glucose and other organic molecules. Blood carries carbon dioxide waste from cellular respiration to lungs and then out of the body. BREATHING AND CELLULAR RESPIRATION (CON’T)

19. Breathing Cellular Respiration Muscle cells carrying out CO 2 + H 2 O + ATP Lungs Bloodstream CO 2 O2O2 O2O2 Glucose + O 2

20. The goal of cellular respiration is to make ATP! Cellular respiration is an exergonic process that transfers energy from the bonds in glucose to ATP. Cellular respiration produces 38 ATP molecules from each glucose molecule This is only 40% of the glucose molecule. The other 60% is lost as heat. Other foods (organic molecules) can be used as a source of energy as well GOAL OF CELLULAR RESPIRATION = ATP

21. C 6 H 12 O 6 + 6O2O2 Glucose Oxygen 6 CO 2 Carbon dioxide + 6 H2OH2O Water + ATPs Energy

22. Uses the ATP made from cellular respiration for all of its functions. Heart pumping, breathing, maintaining body temperature Body maintenance just to keep us alive uses 75% of the energy a person takes in, in a typical day.  A kilocalorie (kcal) is the quantity of heat required to raise the temperature of 1 kilogram (kg) of water by 1 o C  The average adult human needs about 2,200 kcal of energy per day HUMAN BODY

24. Cellular respiration is the controlled breakdown of organic molecules – Energy is released in small amounts that can be captured by a biological system and stored in ATP Energy available to a cell is found in the arrangement of electrons in the chemical bonds that hold glucose together. Electrons are moved to oxygen as the C – H bonds of glucose are broken down and the H – O bonds of water are formed. ROLE OF ELECTRONS

25. Oxygen is very electronegative so the electrons are attracted to it. As the electrons “fall”(move) to the oxygen they lose potential energy. It is like stepping down an electron staircase Energy is released in small amounts ROLE OF ELECTRONS (CON’T)

26. Redox reactions - Movement of electrons from one molecule to another Oxidation – loss of electron from one substance Reduction – addition of an electron to another substance An “oxidized” molecule is when it loses electrons. A “reduced” molecule is when it gains electrons OXIDATION – REDUCTION REACTIONS

27. C 6 H 12 O 6 + 6 O 2 Glucose Loss of hydrogen atoms (oxidation) 6 CO 2 + 6 H 2 O + Energy Gain of hydrogen atoms (reduction) (ATP) OXIDATION – REDUCTION REACTIONS Glucose loses electrons and becomes oxidized Oxygen gains electrons and becomes reduced

28. Enzymes are necessary to oxidize glucose and other foods The enzyme that removes hydrogen from an organic molecule is called dehydrogenase Dehydrogenase requires a coenzyme called NAD + (nicotinamide adenine dinucleotide) to shuttle electrons NAD + can become reduced when it accepts electrons and oxidized when it gives them up NECESSARY ENZYME AND COENZYME

29. Dehydrogenase strips 2 hydrogen atoms from glucose At the same time NAD + picks up the 2 electrons and becomes reduced to NADH. One proton is released. The electrons from NADH are sent to the electron transport chain. Electron transport chain are electron carriers built into the inner membrane of a mitochondrion. NECESSARY ENZYME AND COENZYME

30. 2 H + + 2 e – Oxidation Dehydrogenase Reduction NAD + + 2 H NADH + H+H+ (carries 2 electrons)

31. The electron transport chain has a bunch of redox reactions happen where electrons are sent from carrier to carrier down to oxygen. Oxygen is the final electron acceptor. NECESSARY ENZYME AND COENZYME

32. ATP NAD + NADH H+H+ H+H+ 2e – Electron transport chain Controlled release of energy for synthesis of ATP + O2O2 H2OH2O 1212

33. Happens in 3 steps 1. Glycolysis – splitting of glucose – Happens in the cytoplasm – Glucose (6C) is broken down into 2 pyruvate (3C) molecules – Little ATP is made 2. Citric Acid Cycle (CAC) – Happens in mitochondria – The citric acid cycle breaks down pyruvate into carbon dioxide and supplies the third stage with electrons – Little ATP is made OVERVIEW OF CELLULAR RESPIRATION

34. 3. Oxidative Phosphorylation – During this stage, electrons are shuttled through the electron transport chain – As a result, ATP is generated through oxidative phosphorylation associated with chemiosmosis – This stage occurs in the inner mitochondrion membrane OVERVIEW OF CELLULAR RESPIRATION

35. – During the transport of electrons, a concentration gradient of H + ions is formed across the inner membrane into the intermembrane space – The potential energy of this concentration gradient is used to make ATP by a process called chemiosmosis – The concentration gradient drives H + through ATP synthases and enzymes found in the membrane, and ATP is produced CELL RESPIRATION VIDEO OVERVIEW OF CELLULAR RESPIRATION

36. Mitochondrion CO 2 NADH ATP High-energy electrons carried by NADH NADH C ITRIC A CID C YCLE G LYCOLYSIS Pyruvate Glucose and FADH2 Substrate-level phosphorylation Substrate-level phosphorylation O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) Oxidative phosphorylation ATP Cytoplasm Inner mitochondrial membrane

37. A single molecule of glucose is cut in half by enzymes through a series of steps to produce two molecules of pyruvate 2 molecules of NAD + are reduced to two molecules of NADH 2 molecules of ATP are produced by substrate-level phosphorylation – Substrate-level phosphorylation - an enzyme transfers a phosphate group from a substrate molecule to ADP, forming ATP GLYCOLYSIS

38.  ADP ATP Substrate Enzyme Product Enzyme P P P

39. Glucose NAD + + 2 2 ADP NADH2 P2 2 ATP 2 + H+H+ 2 Pyruvate

40.  ATP can be used immediately  NADH must be transported through the electron transport chain to generate additional ATP  Glycolysis is broken down into many steps each with a specific enzyme GLYCOLYSIS

41.  It can be divided though into 2 phases  Phase 1 – Energy Investment Phase (steps 1-4)  Energy is consumed  2 ATPs are used  Phase 2 – Payoff Phase (steps 5-9)  2 NADH molecules are made  4ATP are made  NET gain of ATP is only 2 ATP!! For 1 glucose molecule

42. Steps 6 – 9: ATP and pyruvate are produced. Step 5: A redox reaction generates NADH. Step 4: A six-carbon intermediate splits Into two three-carbon intermediates. ENERGY INVESTMENT PHASE Glucose Glucose-6-phosphate 1 Fructose-6-phosphate Step ADP ATP P 3 ADP ATP P 2 P 4 P Fructose-1,6-bisphosphate 5 5 PP P P P P NAD + P P ENERGY PAYOFF PHASE Glyceraldehyde-3-phosphate (G3P) 1,3-Bisphosphoglycerate NADH NAD + NADH + H + ADP ATP 6 6 3-Phosphoglycerate 2-Phosphoglycerate 7 7 8 8 PP PP P P H2OH2OH2OH2O ADP ATP 9 9 Phosphoenolpyruvate (PEP) Pyruvate Steps 1-3: A fuel molecule is energized, using ATP.

43. ENERGY INVESTMENT PHASE Glucose Glucose-6-phosphate Fructose-6-phosphate Step ADP ATP P ADP ATP P P P Fructose-1,6-bisphosphate 1 2 3 Steps 1 – 3:A fuel molecule is energized, using ATP.

44. Glucose Glucose-6-phosphate Fructose-6-phosphate Step ADP ATP P ADP ATP P P P Fructose-1,6-bisphosphate 1 2 3 Glyceraldehyde-3- phosphate (G3P) Step 4: A six-carbon intermediate splits Into two three-carbon intermediates. P P 4 ENERGY INVESTMENT PHASE Steps 1 – 3:A fuel molecule is energized, using ATP.

45. P P P P NAD + P P ENERGY PAYOFF PHASE 1,3-Bisphosphoglycerate NADH  H + Step 5: A redox reaction generates NADH. 5 5 Glyceraldehyde-3-phosphate (G3P) P P NAD + NADH  H +

46. P P P P NAD + P P 1,3-Bisphosphoglycerate NADH  H + ADP ATP 3-Phosphoglycerate 2-Phosphoglycerate P P P P P P H2OH2O H2OH2O ADP ATP Phosphoenolpyruvate (PEP) Pyruvate Steps 6 – 9: ATP and pyruvate are produced. 5 5 Glyceraldehyde-3-phosphate (G3P) P P NAD + NADH  H + 6 6 7 8 9 8 9 7 Step 5: A redox reaction generates NADH. ENERGY PAYOFF PHASE

47. GLYCOLYSIS ANIMATION

48. BEFORE CITRIC ACID CYCLE (OXIDATION OF PYRUVATE) The pyruvate formed in glycolysis is transported to the mitochondria, where it is prepared for entry into the citric acid cycle – STEP 1: Removal of a carboxyl group that forms CO 2 – STEP 2: Oxidization of the two-carbon compound remaining so NADH is made – STEP 3: Coenzyme A binds to the two-carbon fragment forming acetyl coenzyme A

49. Coenzyme A Pyruvate Acetyl coenzyme A CoA NAD + NADH  H + CO 2 1 3 2

50. CITRIC ACID CYCLE (KREBS CYCLE) Happens in the matrix of the mitochondria The two carbon acetyl part of acetyl co-A becomes part of the CAC cycle The co-A part is removed and recycled The acetyl group (2C) joins with a four-carbon molecule forming a six-carbon molecule The six-carbon molecule then passes through a series of redox reactions that regenerate the four-carbon molecule (thus the “cycle” designation)

51. There are many steps to the CAC cycle Each step has its own specific enzyme Each turn of the cycle makes – 1 ATP by substrate level phosphorylation – 3 NADH – 1 FADH 2 However, since there are two molecules of acetyl co-A from the intial glucose, we get a total of: – 2 ATP by substrate level phosphorylation – 6 NADH – 2 FADH 2

52. C ITRIC A CID C YCLE NAD + NADH 3 H + CO 2 + 3 3 2 CoA Acetyl CoA P ADP + ATP FADH2 FAD

53. C ITRIC A CID C YCLE CoA 2 carbons enter cycle Acetyl CoA CoA 1 Oxaloacetate Step 1: Acetyl CoA stokes the furnace.

54. C ITRIC A CID C YCLE CoA 2 carbons enter cycle Acetyl CoA CoA 1 Oxaloacetate Step 1: Acetyl CoA stokes the furnace. 2 3 NAD + NADH CO 2 Citrate ADP + + H + P Alpha-ketoglutarate leaves cycle ATP NAD + NADH CO 2 + H + leaves cycle Steps 2 – 3: NADH, ATP, and CO 2 are generated during redox reactions.

55. C ITRIC A CID C YCLE CoA 2 carbons enter cycle Acetyl CoA CoA 1 Oxaloacetate 2 3 NADH CO 2 Citrate ADP  P Alpha-ketoglutarate leaves cycle ATP NADH CO 2 leaves cycle 5 NAD + NADH Malate + H + 4 FADH2 FAD Succinate Steps 4 – 5: Redox reactions generate FADH2 and NADH. NAD + + H + NAD + + H + Step 1: Acetyl CoA stokes the furnace. Steps 2 – 3: NADH, ATP, and CO 2 are generated during redox reactions.

56. WHAT HAS BEEN MADE FROM GLYCOLYSIS AND CITRIC ACID CYCLE? 4 ATP 10 NADH 2 FADH 2 The NADH and FADH 2 will be used in the ETC! We also see the release of 6 CO2 molecules – 2 from pyruvate grooming and 4 from the CAC.

57. CITRIC ACID CYCLE ANIMATION

58. Involves the electron transport chain, chemiosmosis and oxygen  NADH and FADH 2 are also involved  ETC is found in the inner membrane of the mitochondria  A H + ion gradient formed from all of the redox reactions of glycolysis and the citric acid cycle provide energy for the synthesis of ATP OXIDATIVE PHOSPHORYLATION

59. Electron transport chain has electron carriers in the membrane that use the chemical energy released by redox reactions to make a H+ gradient and then to make ATP through chemiosmosis. ELECTRON TRANSPORT CHAIN

60. ATP H+H+ Intermembrane space O2O2 H2OH2O 1212 Inner mitochondrial membrane H+H+ NAD + H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Mitochondrial matrix Electron flow Electron carrier Protein complex of electron carriers NADH FADH2FAD ATP synthase P ADP + Chemiosmosis + 2 O XIDATIVE P HOSPHORYLATION Electron Transport Chain

61. NADH and FADH 2 donate their electrons to the ETC Electrons move through the chain to oxygen because oxygen is so electronegative. Each oxygen atom accepts 2 electrons from the chain and picks up 2 hydrogen from the solution to make water (bi-product of cellular respiration) All of the carriers in the chain bind and release electrons in redox reactions OXIDATIVE PHOSPHORYLATION

62. 3 of the protein complexes in the chain use the energy from the electron transfer to actively transport H + across the membrane from where H + is less concentrated to where it is more concentrated – This increases the concentration gradient The H + moves from the matrix to the intermembrane space The H + ions want to diffuse back across but can only move through the ATP synthase. OXIDATIVE PHOSPHORYLATION

63. As the H + move through the ATP synthase, it cause parts inside the synthase to rotate which allows for a phosphate to be added to ADP to make ATP This whole process happens from oxidation-reduction reactions. OXIDATIVE PHOSPHORYLATION

64. ANIMATION

65. Poisons can block the ETC so ATP cannot be made because no H + gradient is made Ex- cyanide and carbon monoxide Some antibiotics block the ATP synthase of bacteria. POISONS AND CELLULAR RESPIRATION

66. Glycolysis – occurs in the cytoplasm Alteration of pyruvate CAC – occurs in the mitochondria ETC – the inner membrane of mitochondria Glycolysis and CAC – produce 4 ATP by substrate level phosphorylation Oxidative phosphorylation– produces 34 ATP Each NADH can produce at maximum 3 ATP Each FADH 2 can produce at maximum 2 ATP So 38 ATP maximum made as well as CO 2 and H 2 O REVIEW

67. Cytoplasm Glucose FADH 2 Mitochondrion Maximum per glucose: O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) C ITRIC A CID C YCLE Electron shuttle across membrane 2 NADH 2 2 6 2 (or 2 FADH 2 ) 2 Acetyl CoA G LYCOLYSIS 2 Pyruvate About 38 ATP  about 34 ATP by substrate-level phosphorylation by oxidative phosphorylation  2 ATP by substrate-level phosphorylation  2 ATP

68. Fermentation is an anaerobic (without oxygen) energy- generating process Just uses glycolysis because no oxygen is needed Just makes a net of 2 ATP, 2 pyruvates, and NADH  The trick is to oxidize the NADH without passing its electrons through the electron transport chain to oxygen FERMENTATION

69. Still allows your muscles to work a little when not enough oxygen is present Microorganisms use this NADH has to be recycled back to NAD + Two types – lactic acid and alcohol fermentation FERMENTATION

70. LACTIC ACID FERMENTATION Pyruvate is reduced to lactate so NADH can be oxidized to NAD + Lactate goes to liver where it is changed back into pyruvate. Cheese and yogurt Leads to sore muscles Glucose NADH NAD + 2 2 NADH 2 NAD + 2 2 ADP P ATP 2 2 Pyruvate 2 Lactate GLYCOLYSIS Lactic acid fermentation  2

71. ALCOHOL FERMENTATION Brewing, wine, baking Yeast – both aerobic and anaerobic conditions Pyruvate gets converted to carbon dioxide and ethanol while oxidizing NADH back to NAD + Obligate anaerobes – oxygen is poison to them. Faculative anaerobe – can make ATP by either by fermentation or oxidative phosphorylation (muscle cells) 2 ADP P ATP 2 GLYCOLYSIS NADH NAD + 2 2 NADH 2 NAD + 2 2 Pyruvate 2 Ethanol Alcohol fermentation Glucose CO 2 2 released  2

72. Happens in almost all organisms So it had to evolve early on Happens in the cytoplasm and not in any organelle Can happen whether oxygen is present or not GLYCOLYSIS AND EVOLUTION

73. Fats, proteins and carbohydrates are all used for cellular respiration. Carbohydrates get broken down into monosaccharides and then enter glycolysis Proteins get broken down into amino acids. – The amino groups are removed and then they enter the CAC or glycolysis – The byproduct of using amino acids is ammonium, which is toxic. Fats get broken down into glycerol and fatty acids – Glycerol – is G3P which is an intermediate in glycolysis – Fatty acids – are broken down into 2 carbon fragments which enter the CAC cycle ORGANIC MOLECULES

74. Food, such as peanuts ProteinsFatsCarbohydrates Glucose O XIDATIVE P HOSPHORYLATION (Electron Transport and Chemiosmosis) CITRIC ACID CYCLE Acetyl CoA GLYCOLYSIS Pyruvate Amino acids Glycerol Sugars Fatty acids Amino groups G3P ATP

75. Not all food molecules are used to make ATP They are also used for biosynthesis Biosynthesis – making of organic molecules using energy requiring metabolic pathways Many metabolic pathways are involved in biosynthesis of biological molecules – To survive, cells must be able to biosynthesize molecules that are not present in its foods – Often the cell will convert the intermediate compounds of glycolysis and the citric acid cycle to molecules not found in food BIOSYNTHESIS

76. Cells, tissues, organisms Proteins Fats Carbohydrates Glucose ATP needed to drive biosynthesis CITRIC ACID CYCLE Acetyl CoA GLUCOSE SYNTHESIS Pyruvate Amino acids Glycerol Sugars Fatty acids Amino groups G3P ATP

77. Cytoplasm Glucose Oxidative phosphorylation (Electron Transport and Chemiosmosis) Citric acid cycle Glycolysis Pyruvate CO 2 ATP CO 2 ATP NADH and FADH 2 Mitochondrion NADH ATP

78. (a) glucose and organic fuels has three stages produce some generates Cellular respiration uses H + diffuse through ATP synthase by process called chemiosmosis energy for cellular work uses (b) (d) (c) (f) (e) oxidizes C 6 H 12 O 6 to pull electrons down to uses pumps H + to create H + gradient produces many