Glycolysis
- Happens in the cytoplasm of all cells
- It can take place in anaerobic or aerobic conditions.
- Glucose (6C sugar) is broken down to 2 molecules of pryuvate (3C compound)
Stage 1. Phosphorylation
- Glucose (6C sugar) - very stable - needs to be activated to be split
- An ATP molecule is hydrolysed - phosphate group attached to glucose at carbon 6
- Glucose > Fructose 6 phosphate
- Another ATP is hydrolysed - phosphate group attached to fructose 6 phosphate at carbon 1
- Activated - fructose 1,6 bisphosphate aka hexose, 1,6-bisphosphate
- Energy from hydrolysed ATP activates the sugar and prevents it from going out of the cell
2. Splitting hexose 1,6 bisphosphate
- each molecules of hexose 1,6 bisphosphate is splt into 2 x triose phosphate
3. Oxidation of triose phosphate
- 2H atoms are removed from triose phosphate (involves dehydrogenase enzymes)
- These are helped by NAD which is a H acceptor - combines with H and becomes 'reduced NAD'
- 2 ATP formed - substrate level phosphorylation
4. Conversion triose phosphate > pryuvate
- 4 enzyme-catalysed reactions convert each phosphate to a pryuvate
- during this, 2 molecule of ADP are phosphorylysed to 2 ATP
So overall, 2 molecules of ATP (=net amount - 4 have been made but 2 are used again)
There are also 2 molecules of reduced NAD and 2 pryuvate which ill be used in next stage of respiration
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