Glycolysis

Glycolysis

1. STEP ONE

   • Phosphorylation
     • Two molecules of ATP are used to add phosphate to glucose
       • This results in hexose bisphosphate which is more reactive than glucose
         • ready for the next steps in breaking down the glucose

2. STEP TWO

   • Lysis of glucose molecule
     • Hexose is broken into two molecules of glycerate-3-phosphate (GP)

3. STEP THREE

   • Formation of pyruvate
     • NAD is reduced to form NADH (reduced co-enzyme)
       • by removing hydrogen atoms from GP
         • THIS IS DEHYDROGENATION
           • Four molecules of ATP are formed using energy released as bonds are formed
             • These four ATP molecules give the net two ATP produced by glycolysis
               • two ATP were used in Step One
                 • The ATP is produced by substarte level phosphorylation, which is different from the ATP production in the mitochondrion (oxidative phosphorylation).Additional 
                 • phosphorylation
           • GP is oxidised as a result

4. Typical Question:

   • showing worked example
   • Give reasons to explain that the energy for ATP production during glycolysis
     • is provided by oxidation, despite the fact that oxygen is not required
       • Removal of hydrogen atoms from GP is a form of oxidation
         • Oxidation is the addition of oxygen OR
           • the removal of hydrogen or an electron
             • Energy is transferred to ATP molecules in substrate level phosphorylation