Krebs cycle

The Krebs cycle (or de Szent-Györgyi and Krebs cycle, or yet again, the citric acid cycle) is a metabolic pathway which takes place in all cells in the cytoplasm of bacteria or in the mitochondria of eukaryotes.

Role of the Krebs cycle

The Krebs cycle plays a role in carbohydrate, lipid, and protein metabolism but it is particularly known for enabling production of cellular energy in the form of the GTP de molecule. It produces one of these per cycle from a GDP molecule.

The molecules involved in the Krebs cycle

A molecule of citrate is gradually changed by enzymes in the presence of cofactors. There is a total of eight stages or eight molecules from the starting citrate to the final citrate:

• citrate ;
• isocitrate ;
• alpha-ketoglutarate ;
• succinyl CoA ;
• succinate ;
• fumarate ;
• malate ;
• oxaloacetate ;
• citrate.

Other molecules involved are acetyl-CoA, water, le carbon dioxide(CO₂), NADH, le FADH2, and GTP etc.

Summary of the Krebs cycle

In total the Krebs cycle produces :

• 2 molecules of CO₂ ;
• 3 molecules of NADH,H+ ;
• 1 molecule of CoQH₂ ; and
• 1 molecule of GTP.