OCR Biology respiration 5.2.2 revision summary - By A* Student

1. Glycolysis
Glucose (6C) - Cell cytoplasm
ATP ADP + Pi (phosphorylation of glucose) - aerobic & anaerobic
(enzyme Glucokinase)
Glucose 6 Phosphate
(isomerisation) Phosphorylation
- Changes glucose molecule
Fructose 6 so it cannot move back
Phosphate out of cell
ATP ADP + Pi (phosphorylation of glucose) - Maintains glucose conc
gradient
Fructose 1,6
Biphosphate
Triose Phosphate (3C) Triose Phosphate (3C)

Dehydrogenation = redNAD produced ATP produced by substrate
Pi + ADP ATP (by substrate level level phosphorylation
phosphorylation) (removal of Phosphate from
Intermediate compound compound in pathway)
Coenzyme NAD transports
Dehydrogenation = redNAD produced
hydrogen atoms
Pi + ADP ATP (by substrate level
phosphorylation)
Pyruvate(3C) Pyruvate(3C)


Glycolysis Products = 4 ATP made – 2 ATP used = 2 ATP, 2
reduced NAD
2. Krebs cycle Pyruvate(3C)
Link reaction
- into mitochondrial matrix Decarboxylation = CO2 released
- only aerobic Dehydrogenation = redNAD produced
- 2 pyruvate per 1 glucose
Products per 1 cycle Acetate (2C)
3x CO2
4x reduced NAD
1x reduce FAD Acetyl CoA CoA
1x ATP
Per glucose = x2
Acetate (2C)

Oxaloacetate (4C) Citrate 6C

Dehydrogenation = redNAD produced Decarboxylation = CO2 released
Dehydrogenation = redNAD produced

4C compound 5C compound

Dehydrogenation = redFAD produced Decarboxylation = CO2 released
Dehydrogenation = redNAD produced

4C compound 4C compound

ATP Isomerisation results in
ADP + Pi
production of ATP by
substrate level
phosphorylation