BSCI 230 Today, 2/15/01

Lecture 6 - Glycolysis - TCA

  • Review procedures for posting to eCell
  • Any problems or concerns?
  • Introduction of recitation TAs
  • Demotivational thought for the day
  • Glycolysis, oxidation of pyruvate, Krebs TCA Cycle, and oxidative phosphorylation

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    Your Recitation Leaders:

  • Carsten
  • Darren
  • Diane
  • Lauren
  • Lisa
  • Mario
  • Michael
  • Payman
  • Usman

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    Oops!

    C6H12O6 + 6O2 <---> 6CO2 + 6 H2O

    DG = - 686 kcal/mole


  • Oxidation of (CH2O)6
  • Substrate Level Phosphorylation
  • Chemiosmotic Synthesis
  • NAD+ and FAD

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    Substrate-Level Phosphorylation

    (SLP)

    Summary of Chemiosmotic Synthesis of ATP

    1. High energy e- carried by NADH and FADH2
    2. To mitochondrial ETS on cristae
    3. e- loses energy on ETS which uses it to pump H+ into intermembrane space
    4. [H+] gradient used to allow H+ diffuse through ATP synthase and make ATP

    Electrons to the Electron Transport System
    Mitochondrial Inner Membrane: Cristae
     

    Electrons to the Electron Transport System/Mitochondrial Inner Membrane: Cristae Electrons to the Electron Transport System/Mitochondrial Inner Membrane: Cristae



     
     
     
     
     
     
     

    To Our Handout:

    What to know for each process!!!

  • What you start with
  • What you end with
  • Where it occurs?
  • Whatís the point?

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    Click here for to enlarge diagram.

    Glycolysis

    Glucose (6C) +2 NAD+ + 2 ATP --->

    2 Pyruvate (3C) + 2 NADH + 2 H+ + 4 ATP

    Glycolysis

  • Cytoplasmic
  • Uses 2 ATP to generate 4 ATP
  • Net gain of 2 ATP
  • Generates ATP anaerobically by SLP

    •    - Relatively low yield of energy
  • Generates 2 NADH

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    Glycolysis

     

    Fate of Pyruvate in the absence of oxygen:
    Fermentation
    Fig 13-9

    Purpose: regenerate NAD+ to allow anaerobic glycolysis and SLP to occur
    Fate of Muscle Lactate
    (Running is bad for you)


  • Anaerobic conditions: muscles can make ATP by SLP but lactate builds up
  • Recovery phase involves gluconeogenesis in the liver
  • Cori Cycle
  • Endergonic, reduction reaction

    • Regulation of Glycolysis by Allosteric Mechanisms

  • Activation by ADP and AMP
  • Inhibition by Acetyl CoA and ATP
  • See Fig 13-13 to be sure you understand the theory behind these allosteric actions

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    Pyruvate Oxidation

    Pyruvate + Coenzyme A* + NAD+ --->
                Acetyl CoA + CO2 + NADH + H+
     
              *written as CoA-SH

     

    Tricarboxylic Acid Cycle


    Step 1:
    Acetyl CoA (2C) + Oxaloacetate (4C) ---> Citrate (6C) + CoA-SH

     

    Pyruvate Oxidation