Glycolysis is the first stage of cellular respiration, it occurs within the cytoplasm of the cell, it involves the splitting of a sugar (hence the name: glycolysis). The best sugar to use in glycolysis is glucose, but other sugars can be used instead. The point of glycolysis is to convert a single molecule of whatever sugar is at hand into 2 pyruvate molecules.


This is assuming glucose is the sugar in use.

  • Glucose is converted into glucose 6-phosphate phosphorylated by an ATP molecule to lower its activation energy, which means the process can start.
  • Glucose 6-phosphate is rearranged to into fructose 6-phosphate to prevent it leaving the cytoplasm.
  • Fructose 6-phosphate is phosphorylated by another ATP molecule, converting it into fructose 1,6-diphosphate.
  • Fructose 1,6-diphosphate is split into two molecules: dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GP).

Remember that the reactions after this point occur twice because the sugar has been split.

  • The molecule is phosphorylated by a free-floating inorganic phosphate group in the cytoplasm, and is also oxidised be an NAD molecule via the removal of hydrogen, the molecule (whichever of the two it may be) is converted into 1,3-diphosphoglyceric acid.
  • The 1,3-diphosphoglyceric acid is now dephosphorylated and the phosphate group is given to an ADP molecule in the cytoplasm to form a molecule of ATP and 3-phosphoglyceric acid.
  • 3-phosphoglyceric acid is now dephosphorylated once again to produce another molecule of ATP and pyruvate.


Gained to produce.Edit

It will aslo help with gaining energy to be able to reproduce etc.

  • 4 ATP molecules
  • 2 reduced NAD (also written as NADH+H+ or NADH2)
  • 2 pyruvate molecules

Lost due to implication with energyEdit

What is used up in the process:

  • 2 ATP molecules

Net GainEdit

The profit of this reaction:

  • 2 ATP molecules
  • 2 reduced NAD
  • 2 pyruvate molecules