8.2 Cell Respiration

8.2 Cell Respiration

1. Nature of Science

   • Paradigm shift: the chemiosmotic theory led to a paradigm shift in the field of bioenergetics
     • TOK
       • Peter Mitchell's chemisosmotic theory encountered years of opposition before it was finally accepted
         • For what reasons does falsification not always result in an immediate acceptance of new theories or a paradigm shift

2. Structure of mitochondrion

   • Electron tomography used to produce images of active mitochondria
     • Annotation of a diagram of a mitochondrion

3. Analysis of diagrams of the pathways of aerobic respiration

   • Redox reactions
     • Oxidation
       • Oil: Oxidation Is Loss of electrons
     • Reduction
       • RIG: Reduction Is Gain of electron
   • Glycolysis
     • Glucose is converted to pyruvate in the cytoplasm
       • Phosphorylation
         • Lysis
           • Oxidation
             • Small net gain of ATP
   • Link reaction
     • Pyruvate
       • Oxidative Decarboxylation
         • H is removed from pyruvate
           • H is accepted by NAD+ giving NADH + H+
         • CO2 production
         • Pyruvate converted into an acetyl group
           • Acetyl group accepted by coenzyme A (CoA)
             • Acetyl CoA enters the Krebs cycle
   • Krebs cycle
     • Oxidation of the acetyl groups
       • Reduction of H carriers
         • Decarboxylation
           • Substrate level phosphorylation
             • ATP Formation
           • Release of CO2
         • NADH + H+ = NAD+ FADH2 + H+ = FAD
           • Energy released by oxidation reactionsis carreid to the cristae fo the mitochondrai by reduced NAD+ and FAD
             • Electron Transport Carriers (ETC)
               • Transfer of electrons between carriers in the electron transport chain in the membrane of the cristae is coupled to proton pumping
                 • Oxidative phosphorylation = Chemiosmosis
                   • Protons diffuse through ATP synthase to generate ATP
                 • Oxygen is needed to bind with the free protons to maintain the H gradient
                   • Water formation