Mnemonics Cytosol
Glycolysis
Glucose to pyruvate, ten steps, no oxygen required.
Net 2 ATP · 2 NADH · 2 pyruvate per glucose
Intermediates
Goodness Gracious Father Frank Did Go Buy Pickled Pumpkins To Prepare Pies
Enzymes
Hungry Pirates Pick All The Greatest Pickled Pumpkins Ever Picked
This mnemonic,
unpacked word by word →
Glycolysis invests 2 ATP to receive 4 ATP. Everything after aldolase happens twice per glucose.
1
Glucose
Glucose-6-phosphate
Hexokinase regulated ATP → ADP
“Gracious” → Glucose-6-phosphate
·
“Hungry” → Hexokinase
Glucokinase in liver and pancreatic β-cells: higher Km, so it only engages when glucose is abundant. Hexokinase is inhibited by its own product, G6P.
2
Glucose-6-phosphate
Fructose-6-phosphate
Phosphoglucose isomerase
“Father” → Fructose-6-phosphate
·
“Pirates” → Phosphoglucose isomerase
Aldose to ketose. G6P is also the branch point into the pentose phosphate pathway and glycogen synthesis.
3
Fructose-6-phosphate
Fructose-1,6-bisphosphate
Phosphofructokinase-1rate-limiting ATP → ADP
“Frank” → Fructose-1,6-bisphosphate
·
“Pick” → Phosphofructokinase-1
The committed, rate-limiting step of glycolysis. Inhibited by ATP and citrate; activated by AMP and fructose-2,6-bisphosphate.
4
Fructose-1,6-bisphosphate
G3P + DHAP
Aldolase
“Did / Go” → G3P + DHAP
·
“All” → Aldolase
Cleaves the six-carbon chain between C3 and C4 into two three-carbon pieces.
5
Dihydroxyacetone phosphate
Glyceraldehyde-3-phosphate
Triose phosphate isomerase
“The” → Triose phosphate isomerase
Converts DHAP to G3P, so one glucose yields two G3P. Every step below runs twice.
6
Glyceraldehyde-3-phosphate
1,3-Bisphosphoglycerate
GAP dehydrogenase ×2 per glucose NAD⁺ → NADH
“Buy” → 1,3-Bisphosphoglycerate
·
“Greatest” → GAP dehydrogenase
Adds inorganic phosphate from solution. This is where glycolysis produces its NADH.
7
1,3-Bisphosphoglycerate
3-Phosphoglycerate
Phosphoglycerate kinase ×2 per glucose ADP → ATP
“Pickled” → 3-Phosphoglycerate
·
“Pickled” → Phosphoglycerate kinase
Substrate-level phosphorylation. Pays back the two ATP invested.
8
3-Phosphoglycerate
2-Phosphoglycerate
Phosphoglycerate mutase ×2 per glucose
“Pumpkins” → 2-Phosphoglycerate
·
“Pumpkins” → Phosphoglycerate mutase
Relocates the phosphate from C3 to C2.
9
2-Phosphoglycerate
Phosphoenolpyruvate
Enolase ×2 per glucose releases H₂O
“Prepare” → Phosphoenolpyruvate
·
“Ever” → Enolase
Dehydration creates the high-energy enol phosphate. Inhibited by fluoride.
10
Phosphoenolpyruvate
Pyruvate
Pyruvate kinase regulated ×2 per glucose ADP → ATP
“Pies” → Pyruvate
·
“Picked” → Pyruvate kinase
Substrate-level phosphorylation. Activated by F-1,6-BP (feed-forward), inhibited by ATP and alanine.