BIOL 111 301 1st Edition Lecture 10Outline of Last Lecture I. How do you get energy from Redox reactions?I. How do you systematically remove e-?II. Catabolic pathways yield energyIII. Overview Of Cellular RespirationIV. GlycolysisOutline of Current LectureI. Review quizII. GlycolysisIII. Junction ReactionsIV. Overview of the citric acid cycleV. Mitochondrial structureVI. Oxidative phosphorylationVII. How much energy (# ATP) was harvest4ed from glucose?Current Lecture- Review quizo What do you need to remove pairs of e-?o What are the net products of glycolysis?o Name 3 enzymes and 4 substrates you need to know from glycolysis. Enzymes: hydrogenase, isomenase, pysomerase Substrates: glucose, pyruvate, G3P, DHAP- Glycolysiso Dehydrogenase-enzyme that removes hydrogens to NAD+- Junction Reactionso With oxygen, pyruvate transported to mitochondria matrixo Enzyme complex pyruvate dehydrogenase catalyzes Decarboxylation of pyruvate (lose one carbon dioxide) 2-C compound oxidized to form acetate, 2e NADH Acetate binds to coenzyme A acetyl CoA- Overview of the citric acid cycleo What does cycle mean? Starts at one place and ends at the same place that it began o What it the carbon input? Output? (follow pink/blue C) For one molecule of glucose, there will be 2 citric acid cycleso Addition phase: 2C + 4C = 6C Acetyl CoA + oxaloacetate = citrateo Removal phase Loss of 2C to 2CO2—decarboxylation 2 pair e- removed to 2 NADH—dehydrogenaseo Regeneration phase CoA displaced by Pi Pi removed to GTP then ATP—substrate level phosphorylation One pair e- removed to FADH2—dehydrogenase One pair e- removed to NADH—dehydrogenase - Mitochondrial structure- Oxidative phosphorylationo Electron transport chain Located in inner mitochondrial membrane Composed of: 4 multiprotein complexes- With cofactors: Fe-S complex OR heme (Fe) groups E-transferred to cofactors via series of redox reactions O2 final e- acceptor H20 Overall drop in delta G from: NADH to -53 kcal/mol and FADH2 to about -40 kcal/mol Many poisons/toxins target these proteinso Chemiosmosis Flow of H+ form hilow used to drive cell work H+ pumped from mito matrix to intermembrane space by transmembrane proteins of e- transport chain Creates potential energyo ATP synthase Power by H+ gradient Multiple proteins: stator (channel), rotor, rod, knob H+ flow thru stator and rotor, turns rod, activates catalytic sites on knobATP formed- How much energy (# ATP) was harvest4ed from glucose?o Given yields: NADH=2.5 ATP FADH2-1.5 ATPo Glycolysis 2 ATP invest + 4 ATP produce = 2 ATP 2 NADH X 2.5 ATP/NADH = 5 ATPo Junction reactions 2 pyruvate X 1 NADH X 2.5 ATP/NADH = 5 ATP (oxidative)o Citric Acid Cycle 2 pyruvate X 1 ATP = 2 ATP (substrate) 2 pyruvate X 3 NADH X 2.5 ATP/NADH = 15 ATP (oxidative) 2 pyruvate X 1 FADH2 X 1.5 ATP/FADH2 = 3 ATP (oxidative)- Total ATP harvested is 32
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