PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18What is the Daily Human Requirement for ATP?Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30FAD, Flavine Adenine DinucleotideSlide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Lecture 14 (Chapter 15) - Metabolism•Metabolism•ATP as the universal currency of free energy•Coupled Reactions•Activated carriers•Regulation of metabolic processes1What is Metabolism?•The complex of physical and chemical processes occurring within a living cell or organism that are necessary for the maintenance of life.•Photosynthesis (autotrophs)•Biosynthesis (anabolism)•Oxidation of fuel molecules (catabolism – chemoheterotroph)2Energy is released from glucose in a stepwise fashion34Oxidation of single-carbon compounds5Two main types of Cellular FuelAox + Bred Ared + BoxReduction --- Gain of e-/loss of oxygen/gain of hydrogenOxidation --- Loss of e-/gain of oxygen/loss of hydrogen6Oxidation-Reduction reactions : OverviewHIGH Enthalpy/LOW Entropy (Higher free energy)Oxidation of carbon fuelOxidation of carbon fuelNADHFADH27Catabolism Metabolism Anabolism LOW Enthalpy/HIGH Entropy (Higher free energy)NADH8The Stages of CatabolismPhosphoric Anhydride Linkages (Phosphoryl Groups with High Transfer Potential)in Adenosine Nucleotides9αβγPhosphoester bond10BASE (Adenine)Sugar (Ribose)Adenosine-5’-Triphosphate (ATP)Arginine Finger & ATPase activityThreonineAspartateΔG°’ = -30.5 kJ mol-1OrthophosphatePi12Hydrolysis of Phosphoric Acid Anhydrides is Highly Favorable∆J+pyrophosphate∆G°’= -45.6 kJ mol-1(PPi)13∆J+pyrophosphate∆G°’= -33.6 kJ mol-1(PPi)--H--H(Pi)(Pi)14Hydrolysis of Pyrophosphate Is Also Thermodynamically FavorableThe High Phosphoryl-transfer Potential of ATP results from structural differences between ATP and its hydrolysis Products1. Electrostatic Repulsion2. Resonance Stability3. Stabilization due to hydration4. Increased entropy15Hydrolysis of ATP Causes the Relief of Charge Repulsion1617Resonance Structures of Orthophosphate (Pi)18There are fewer resonance structures available to the γ-phosphate of ATP than to free orthophosphate.What is the Daily Human Requirement for ATP?•Resting human consume about 40 kg of ATP in 24 hours, and up to 0.5 kg per minute of strenuous exercise.•This is equivalent to 60 kg for a 2-hr run.•The typical adult human body contains 50-100 g of ATP/ADP•Thus each ATP molecule must be recycled nearly 1300 times per day•The typical ATP molecule is consumed within 1 min of its production.191. Substrate-level phosphorylation: Phosphate is transferred to ADP in a coupled reaction involving from a molecule with an high-phosphoryl group transfer potential.2. Creatine kinase3. Oxidative phosphorylation during Cellular respiration by ATP phosphatase20Three ways to make ATP in Eukaryotes21Molecules with High-Phosphoryl Group Transfer PotentialCoupled-Reaction For Production of ATP (Substrate-level Phosphorylation)PEP + H2O pyruvate + Pi ∆G = -62.2 kJ/molADP + Pi ATP + H2O ∆G = +30.5 kJ/molPEP + ADP pyruvate + ATP Overall ∆G = -31.5 kJ/molReactions (1) and (2) are coupled(1)(2)∆G°’overall = ∆G°’reaction 1 + ∆G°’reaction 2If the net ∆G°’ value (∆G°’overall) is sufficiently negative, forming the products (eg. pyruvate and ATP) is an exergonic process (3)22The Large Negative Free Energy Change of ATP Hydrolysis Drives many Unfavorable Reactions in the CellExample: Phosphorylation of glucose is driven by hydrolysis of ATPATP + H2O ADP + Pi ∆G°’reaction 1 = -30.5 kJ/molglucose + Pi G-6-P + H2O ∆G°’reaction 2 = +14 kJ/molglucose + ATP G-6-P + ADP ∆G°’overall = -16.5 kJ/molCoupledreactions23241. Substrate-level phosphorylation: Phosphate is transferred to ADP in a coupled reaction involving from a molecule with an high-phosphoryl group transfer potential.2. Creatine kinase3. Oxidative phosphorylation during Cellular respiration by ATP phosphataseThree ways to make ATP in EukaryotesAnaerobic25Sources of ATP during Exercise1. Transient forms of stored energy(Phosphogen = Creatine phosphate)2. Thermodynamically unstable(Favorable/spontaneous)1. Kinetically stable(Does not hydrolyze unpredictably)26Important properties of high-energy compoundsActivated Carriers during Catabolism•ADP/ATP•NAD+/NADH•FAD/FADH2•FMN/FMNH227reducedoxidizedreduced oxidizedH:- hydride (2 e- + 1 H+) or (H + 1 e-)Error on p. 257 of text (says hydrite H +2 e-)Dehydrogenation Reaction(1 H+ + 1 e-)(1 H+ + 1 e-)28Nicotinamide Adenine Dinucleotide (NAD+)NAD+ Collects Electrons Released in Catabolism2930NAD+ MechanismFAD, Flavine Adenine DinucleotideRiboflavina water-solublevitamin(Vit B2)31FMN, an electron carrier component of the ETC Isoalloxazine ringD-ribitol32Reduction of FAD/FMNorFMNor FMNH23334FAD MechanismActivated Carriers during Anabolism•ADP/ATP•NADP+/NADPH35Reductive (Re-hydration) Biosynthesis36Nicotinamide adenine dinucleotide phosphate (NADP+)37Activated Carrier of Acyl GroupCoenzyme A (CoA or CoASH)Vitamin B5ADP38391. The carriers are kinetically stable in the absence of specific catalysts2. The metabolism of activated groups is accomplished with a small number of carriersTwo characteristics are common to activated carriers40(B9)(B7)(B5)(B3)41Regulation of Metabolic Pathways1. Amounts of enzyme are controlled2. Accessibility to substrates is regulated3. Catalytic activity is regulated•Posttranscriptional modification of enzymes•Allosteric regulation4. Organized into
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