Can I Keep Selling Socks For More Or shall I stop?
Krebs Cycle (Citric Acid Cycle) Intermediates
NEETNEET-PGAIIMSClass 12
Items to Memorize
- Citrate
- Isocitrate
- α-Ketoglutarate
- Succinyl-CoA
- Succinate
- Fumarate
- Malate
- Oxaloacetate
Mnemonic Tricks
How It Maps
| Cue | Maps To |
|---|---|
| Can | Citrate |
| I | Isocitrate |
| Keep | α-Ketoglutarate |
| Selling | Succinyl-CoA |
| Socks | Succinate |
| For | Fumarate |
| More | Malate |
| Or | Oxaloacetate |
Why It Sticks
A frustrated sock vendor wondering if they should continue — the absurdity of selling socks in a metabolic pathway makes it weirdly unforgettable.
A CITRUS farmer (Citrate) was IDENTICAL to his twin (Isocitrate). They went to a KETTLE shop (α-Ketoglutarate) and bought a SUCTION vacuum (Succinyl-CoA) that SUCKED up everything (Succinate). It FUMED with smoke (Fumarate), left a MALT stain (Malate), then turned into an OXO cube (Oxaloacetate) — which dissolved back into citrus juice, completing the cycle!
Why It Sticks
The cycle loops — and so does the story (OXO → citrus juice). Each intermediate connects to a vivid sensory image: sounds, smells, and visual cues that engage multiple memory pathways.
Frequently Asked Questions
How many steps are in the Krebs cycle?
The Krebs cycle has 8 major steps/intermediates: Citrate → Isocitrate → α-Ketoglutarate → Succinyl-CoA → Succinate → Fumarate → Malate → Oxaloacetate. It produces 2 CO₂, 3 NADH, 1 FADH₂, and 1 GTP per turn.
Where does the Krebs cycle occur?
The Krebs cycle occurs in the mitochondrial matrix. Acetyl-CoA (from pyruvate decarboxylation) enters the cycle by combining with Oxaloacetate to form Citrate.
What is the Krebs cycle mnemonic?
'Can I Keep Selling Socks For More Or shall I stop?' — first letters match Citrate, Isocitrate, Ketoglutarate, Succinyl-CoA, Succinate, Fumarate, Malate, Oxaloacetate.
Why is it called the citric acid cycle?
It's named after citric acid (citrate), the first intermediate formed when Acetyl-CoA combines with Oxaloacetate. Hans Krebs described it in 1937, earning the Nobel Prize.
How many ATP does one turn of the Krebs cycle produce?
Directly: 1 GTP (equivalent to 1 ATP). Indirectly: 3 NADH × 2.5 = 7.5 ATP + 1 FADH₂ × 1.5 = 1.5 ATP. Total per turn ≈ 10 ATP equivalents.