Glycolysis

Where does glycolysis occur?

In the cytoplasm of a cell

(It is the 1st stage in both aerobic and anaerobic respiration)

What does glycolysis involve?

The splitting of one 6-carbon molecule of glucose into 2x 3-carbon molecules of pyruvate

Phosphorylation

The addition of a phosphate group to a molecule

Substrate-level Phosphorylation

The formation of ATP without the ETC.

It transfers a phosphate group from a phosphorylated intermediate

Lysis

The splitting/breakdown of a molecule

Dehydrogenation

The removal of hydrogen from a molecule

(oxidation)

Whole Glycolysis Process:

1. Glycolysis → Hexose bisphosphate

   • 2x ATP

     One of the phosphate groups from ATP is removed, making ADP + Pi and the inorganic phosphate that has been removed will be added on to the glucose to form Hexose biphosphate

   • Phosphorylation

2. Hexose bisphosphate → 2x Triose phosphate

   • The hexose bisphosphate is broken down into 2x triose phosphates.

   • Lysis

3. 2x Triose phosphate → 2x Pyruvate

   • 2x NAD will become 2x reduced NAD, through dehydrogenation / oxidation

     4x ATP has been formed as a product of the 2x Triose phosphate → 2x Pyruvate reaction. This process is substrate-level phosphorylation

   • Dehydrogenation

     Substrate-level phosphorylation

What's the overall yield of glycolysis per 1 molecule of glucose?

- 4 molecules of ATP are made, but since 2 are used, the net yield is 2.

- 2 molecules of NADH₂ (2 molecules per 1 molecule of glucose)

- 2 molecules of Pyruvate