Aerobic Resp. & Glycolysis

Stage 1 of Aerobic Resp.

Where does glycolysis occur?

Cytoplasm of cells

• Is an anaerobic process

What happens overall in glycolysis?

1 molecule of glucose (6C) is split into 2 pyruvate molecules (3C each) 

Phosphorylation (step 1 of gly)

1. 2 phosphates are added to glucose from 2 molecules of ATP

   1. Creates 1 hexose-1,6-biphosphate (unstable) and 2 ADPs 

Lysis (step 2 of gly)

1. Hexose-1,6-biphosphate destabilizes and splits 

Produces 2 triose phosphate molecules

Phosphorylation (step 3 of gly) 

A phosphate group is added to each triose phosphate forming 2 triose biphosphate molecules

• Phosphate group from Pi ions present in cytoplasm (free inorganic phosphate ions)

Dehydrogenation (Oxidation) & Formation of ATP (step 4)

1. 2 triose biphosphate molecules are oxidised (H lost)  H added to NAD coenzymes (reducing them)

   1. Forms 2 pyruvate molecules & 2 reduced NAD

2. 4 Phosphate groups added to 4 ADP

   • Produces 4 ATP

Net total of glycolysis

2 ATP

• 2 ATP molecules used up in phosphorylation step1. 

2 red.NAD

• Used in oxidative phosphorylation 

What is glycolysis an example of?

Substrate level phosphorylation

• Formation of ATP without electron transport chain 

• ATP formed by transfer of phosphate group from phosphorylated intermediate (triose biphosphate) to ADP