Aerobic Respiration - Glycolysis

Aerobic respiration is a process:

1. which sugars are broken down - to release energy - in the presence of O2.
2. occurs in three stages: glycolysis, Krebs cycle, electron transport system.

Glycolysis:

1. takes place in cytoplasm of a living cell,
2. glucose --> 2 mol of pyruvate.
3. series of reactions catalysed by specific enzymes
4. involves two phases: energy investment phase and energy pay off phase.

5. Energy investment phase:

• glucose is broken down into 2 mol of PGAL
• 2 mol of ATP are utilized in this phase.

  

6.   Energy pay off phase:

• 2 mol of PGAL --> 2 mol of pyruvate.
• 4 ATP is formed by substrate level phosphorylation.
•  The net = 2 ATP + 2 NADH.