Glycolysis

HideShow resource information
  • Created by: Jelena
  • Created on: 19-03-13 23:44
View mindmap
  • Glycolysis
    • Occurs in the cytoplasm
    • Anaerobic
    • Needs 2 ATP, yields 4 ATP. Net yield of 2 ATP overall.
    • 10 steps
      • 1-5 = preparatory phase
      • 6-10 = payoff phase
    • = "sugar splitting"
    • In some cancers, glycolysis is up-regulated
      • Cancer cells increase rate of glycolysis so they have enough ATP to keep dividing
  • Cellular respiration = C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP
  • STAGE 1: Glucose Mobilization/Activation
    • 2 ATP required
    • Phosphates transferred to glucose via phosphorylation
    • ATP converted to ADP
    • Glucose turns into fructose 1,6-biphosphate
      • Must be cleaved into 2 3-carbon phosphorylated  molecules
  • STAGE 2: Cleavage/Sugar Splitting
    • STAGE 1: Glucose Mobilization/Activation
      • 2 ATP required
      • Phosphates transferred to glucose via phosphorylation
      • ATP converted to ADP
      • Glucose turns into fructose 1,6-biphosphate
        • Must be cleaved into 2 3-carbon phosphorylated  molecules
    • Fructose 1,6-biphosphate split into DHAP and G3P
      • DHAP turns into G3P
  • STAGE 3: Oxidation
    • STAGE 2: Cleavage/Sugar Splitting
      • Fructose 1,6-biphosphate split into DHAP and G3P
        • DHAP turns into G3P
    • Both G3P molecules oxidized
    • Hydrogen atom from G3P is removed and given to NAD+
    • NAD+ becomes NADH
      • NADH used to produce energy later   --> stores energy like a piggy bank
    • Phosphate is attached to the sugars, making them 1,3-biphosphoglycerate
  • STAGE 4: ATP Generation
    • STAGE 3: Oxidation
      • Both G3P molecules oxidized
      • Hydrogen atom from G3P is removed and given to NAD+
      • NAD+ becomes NADH
        • NADH used to produce energy later   --> stores energy like a piggy bank
      • Phosphate is attached to the sugars, making them 1,3-biphosphoglycerate
    • Phosphate groups of molecules given to ADP --> creates ATP
      • Called substrate level phosphoryation
      • Endergonic
    • G3P converted into 3 carbon sugar molecule = pyruvate
    • 4 ATP made
  • Glucose becomes pyruvate
  • ADP becomes ATP
    • Glucose becomes pyruvate
  • NAD+ becomes NADH
    • ADP becomes ATP
    • High amounts of  glucose? --> inc. rate of glycolysis
      • High amounts of pyruvate? --> dec. rate of glycolysis
    • No NAD+ to accept H ion? Pathway stops
      • High amounts of pyruvate? --> dec. rate of glycolysis
    • ATP
      • Endergonic, must be driven by exergonic reaction
    • PFK
      • Catalyses reaction of fructose 6-phosphate to fructose 1,6-biphosphate
        • End Product Inhibition inhibits this --> Prevents breakdown of glucose in pathway that makes ATP
          • More useful for cell to store glucose as glycogen when there is a lot of ATP
      • Enzyme
      • Low concentration? --> ATP binds at active site
        • High concentration? --> ATP binds at regulatory site --> Inhibits PFK, stop phosphorylationof fructose 6-phosphate

    Comments

    No comments have yet been made

    Similar Biology resources:

    See all Biology resources »See all resources »