1. Respiration ATPas currency of energy. Ultra structure of mitochondrion and its functions. Mechanism of aerobic and non aerobic respiration. Significance of respiration.

2. Respiration Energyis stored as organic food in plants. Energy is released when organic food is oxidisedduring respiration. Potential energy in food is converted into kineticenergy. Energy releasing and energy supplying process. The energy released is of two types: Heat energy Chemical energy 3. Definition It is an intracellular oxidation process in which complex organic substances are broken down into simpler substances with stepwise release of energy. 4. Raw materials Glucose OxygenProduct 38 ATPs or 686 Kcal or 2870 KJByproduct Carbon dioxide 5. Reaction C6 H12O6 + 6CO2 Enzymes6H2 O + 6CO2 + 686 Kcal or 38 ATP 6. Overview of RespirationRespiration involves:1. Gaseous exchange External respiration Internal respiration1. Catabolic process Exergonic process Formation of water 7. Types of Respiration1. Aerobic Respiration The oxidation of the glucose with the help of atmospheric oxygen is called aerobic respiration.C6 H12 O6 + 6O2 6CO2 + 6H2 O + 38 ATP2. Anaerobic Respiration The partial oxidation of organic food in the absence of atmospheric oxygen is called anaerobic respiration.C6 H12 O6 2C2 H5 OH + 6CO2 + 2 ATP 8. Aerobic respiration Anaerobic respirationRequires molecular oxygen. Does not molecular oxygen.Respiratory substrate is fully oxidized. Respiratory substrate is incompletely or partially oxidized.End products: CO2 and H2OEnd products: Ethyl alcohol and CO2Exchange of gases between environment andExchange of gases is not involved.organismMetabolic water is formedMetabolic water is not formed.Occurs partly in cytoplasm and partly in Occurs entirely in cytoplasm.mitochondria.38 ATP molecules formed from a glucose 2 ATP molecules from a glucose moleculemolecule.Involve electron transport chain.ETC not required.Process runs continuously throughout life in Occurs continuously only in someplants and animals.microorganisms. In others it takes place temporary for short period during oxygen deficiency. 9. Respiratory substrate The organic substances which are oxidized in cellular respiration for releasing energy are called respiratory substrate.a. Carbohydrates: glucose, fructose, starch, glycogen, sucrose.b. Fats: when carbohydrates are exhausted, fats are used as respiratory source.c. Proteins: used as respiratory substrate under starvation. 10. ATP ATP is energy rich organic compound which storesbiologically usable form of energy. Universal carrier of chemical energy in living world. Energy currency of cells. Energy released when ATP is hydrolyzed to ADP and AMP.ATP + H2 O ADP + ip + 7.3 Kcal Energy is stored when ADP & AMP are phosphorylazed toATP.ADP + ipATP 11. ATP - Structure Itis a ribonucleotide consisting of 3 components:a. Adenineb. Ribosec. Three Phosphate groupsAdenine + Ribose = Adenosine.1st Phosphate group is attached to Ribose and then to each other in a linear fashion. 12. ADENINERIBOSESUGAR PO4 PO4 PO4ADENOSINEPHOSPHATEGROUPS 13. ATP - Functions Storage of energy. Supply of energy. Minimization of energy wastage. Phosphate group donor 14. Mitochondria Double membrane bounded. Center for aerobic respiration. Present in all living eukaryotic cells. Differ in shape. (filamentous, rod shaped). 0.5- 1m in diameter & 2-6m in length. Colorless 15. Mitochondria StructureA) Mitochondrial membranes Outer membrane Inner membrane Cristae Elementary particlesB) Mitochondrial chambers Outer membrane Inner membrane 16. Mitochondrial membraneoOuter membrane- permeable to certain solutes. Consists of 40% lipids & 60% proteins.oInner membrane- consists of 80% proteins & 20% lipids. Selectively permeable.oCristae- inner membrane infolded into the matrix. Encloses a narrow space called intracristal space. Contains enzymes for respirationoElementary particles- present on inner surface of inner membrane. Named as FI particles or Oxysomes. Range between 104-105 in a single mitochondrion. 17. Mitochondrial chamber Outer chamber- present between outer & inner membrane. Filled with watery fluid and few enzymes. It temporarily stores ATP molecules after synthesis. Inner chamber- central cavity of mitochondrion filled with more dense, semi fluid, granular matrix. Matrix contains enzymes, DNA, RNA, ribosomes. 2- 6 circular double stranded of molecule DNA. 18. Mitochondria -Functions Power house of cell Intermediate compounds Calcium storage and its release Thermogenesis Maternal inheritance 19. Aerobic respirationAerobic respiration is completed in Glycolysis Oxidative carboxylation (Acetylation) Krebs cycle Electron transport system 20. Glycolysis The sequence of reactions in which glucose (6C) isbroken down into two molecules of pyruvicacid(3C). Also called as EMP pathway named after theirdiscoverers Embden, Meyerhoff, and Paranas. 1st step in breakdown of glucose. Does not require presence of oxygen & there is nooutput of carbon dioxide. Occurs in cytoplasm of cell. Involves series of 10 reaction, each controlled by aspecific enzyme. 21. The reactions are studied in three groups: Activation or phosphorylation of glucosemolecule. Cleavage or fragmentation Oxidation. 22. Activation 23. Activation or Phosphorylation ofGlucose1. Phosphorylation of glucose Glucose is converted to Glucose 6- phosphate2. Isomerisation Glucose 6- phosphate isomerised to Fructose 6-phosphate.3. Second phosphorylation Fructose 6-phosphate is phosphorylased to Fructose 1, 6-diphosphate by enzyme Phosphofructokinase(PFK). 24. Cleavage or Fragmentation4. Cleavage Fructose 1, 6 bi phosphate is an unstable compound andsplits to produce 3C compounds 3PGAL and DHAP.5. Isomerisation Glycolysis utilizes only PGAL, therefore DHAP isisomerised to 3PGAL 25. Oxidation6. Oxidative phosphorylation(Dehydrogenation): o3PGAL is oxidized by removal of Hydrogen(H2) andsimultaneous phosphorylation of the product resulting in 1,3Di PGA7. ATP synthesis: o 1,3 Di PGA is converted to 3 PGA by release of one phosphate group.8. Isomerization: o Phosphate group at 3rd carbon is shifted to 2nd i.e. 3 PGA to 2PGA. 26. 9. Dehydration : o 2 PGA loses a molecule of water and gets converted to PEPA10. ATP synthesis(formation of Pyruvic acid) oPEPA is converted to Pyruvic acid by removal of phosphategroup. 27. Net reaction of GlycolysisC6H12O6 + 2 ADP +2 NAD+2 C3H4O3 + 2 ATP +2NADH + H+PyruvicacidNet gain of ATP6 ATPFrom 2 NADH2 + 4ATP Directly formed -2ATP Utilized= Net8 ATP gain 28. Fate of Pyruvic Acid GlucoseGlycolysis Pyruvic acidO2 is used O2 is not usedAerobicAnaerobicrespirationrespiration 29. Acetylation Conversion of Pyruvic acid into Acetyl Co- A Reaction starts in cytoplasm and completes in mitochondria Co A +CO2 +Pyruvate(3C)Acetyl Co- A (2C) NAD + NADH2 Pyruvicdehydrogenase 30. Krebs cycle Also called TCA or Citric Acid cycle. Stepwise, cyclic complete oxidation anddecarboxylation of Pyruvic acid into CO2 AND H2O withrelease of energy. Named after Hans Krebs who traced the sequence ofreactions. Takes place in matrix of mitochondria. Des not consume ATP molecules. 31. The reactions are as follows:1.Condensation: Acetyl Co-A (2C) combines with Oxaloacetic acid (4C) in presence of water to form Citric acid(6C).2.Isomerisation: Citric acid first dehydrates to form Cis Aconitic acid and then rehydrates to form Isocitric acid(6C).3.Dehydrogenation: Isocitric acid oxidizes to form Oxalosuccinic acid(6C).4.Decarboxylation: With release of a CO2 Oxalosuccnic acid converts to -Keto glutaric acid(5C). 32. 5.Oxidative decarboxylation: - Ketoglutaric acid oxidizes & decarboxylates and the product combines with Co-A to form Succinyl Co-A (4C).6.ATP synthesis: Succinyl Co-A is hydrolysed to Succinic acid(4C).7.Dehydrogenation: Succinic acid is oxidized to Fumaric acid (4C).8.Hydration: Fumaric acid is converted to Malic acid (4C) by addition of water. Malic acid is then oxidised to form Oxaloacetic acid(4C). 33. Net gain of ATP8NADH2 - 24 ATPATP synthesis through2FADH2- 4 ATPETSDirect synthesis - 2 ATPTotal gain of ATP - 30 ATP 34. Electron Transport System Final step of aerobic respiration. Most ATP and metabolic water generated in this step. Located in inner mitochondrial member(cristae &oxysomes). Individual members are called electron carriers. Electrons from NADH and Succinate pass through theETS to oxygen, which is reduced to water. 35. NADH Succinate Complex IUQ Complex IIComplex IIICytochrome cComplex IV O2 36. Formation of metabolic waterNADH2 or FADH2NAD or FAD + 2H+ + 2e- 2H+ + 2e- + O2H2O 37. Reduced ATP throughDirectSteps Total ATPcoenzymes ETSATP1. 2 NADH2 2NADH2 X 3= 6ATP 2 ATP 8 ATPGlycolysis2. 2 NADH2 2NADH2 X 3 = 6 ATP-6 ATPAcetylation 3. Krebs 6 NADH2 NADH2 X 3 = 18 ATP cycle2 ATP 24 ATP 2 FADH2 FADH2 X 2 = 4 ATPC6 H12 O6 + 6 O26 CO2 + 6 H2 O + 38 ATP 38. Significance of AerobicRespiration 1 glucose molecule produces 38 ATP molecules. Glucose molecule consists 686 k.cal energy. Of these only 277.4 k.cal energy (38 X 7.3 k.cal) isconserved in ATP. Remaining energy is lost as heat energy. Efficiency of this respiration is 40%. 39. Anaerobic respiration The partial incomplete oxidation of organic food in theabsence of atmospheric oxygen is called Anaerobicrespiration. Organisms performing anaerobic respiration are calledanaerobes. In micro organisms it is known as fermentation. No exchange of gases. Only 2 ATP molecules are formed. 40. Mechanism It is completed in 3 main steps.1. Glycolysis2. Decarboxylation3. Reduction 41. Glycolysis First step is similar to glycolysis of aerobic respiration.C6H12O6 + 2ADP +2NAD+2C3H4O3 +2 ATP+2NADH+H+ 42. Decarboxylation Pyruvic acid is decarboxylated to form Acetaldehyde (2C) and CO2 by enzyme pyruvate decarboxylase. Pyruvate Decarboxylas2CH3CO COOH e 2CH3CHO + 2CO2Pyruvic acid Acetaldehyde 43. Reduction Acetaldehyde is reduced to Ethyl Alcohol by NADH2 formed in Glycolysis with the help of enzyme Alcohol Dehydrogenase. Alcohol Dehydrogena seAcetaldehydeEthyl Alcohol 44. Significance of Respiration Releaseof energy Synthesis of ATP Stepwise release of energy Growth and development Energy for biosynthesis Role of intermediates Balance of CO2 & O2 Fermentation 45. Thankyou