also called AKA the Tricarboxylic Acid (TCA) Cycle or the Krebs Cycle.
( đây là 1 trog chuỗi 3 bài về hô hấp tế bào )
The Citric Acid Cycle is one of 3 stages of cellular respiration. The others are glycolysis and electron transport/oxidative phosphorylation.
The big picture: Glycolysis breaks 1 glucose into 2 pyruvate, producing 6 ATP. Pyruvate is used to make acetyl-CoA, the starting product for the citric acid cycle. Each turn of the cycle oxidizes 1 pyruvate, so it takes 2 turns to completely oxidize 1 glucose. Two turns produce 8
, 2 
, and 2 
. and are then oxidatively phosphorylated, resulting in 28 more ATP. The 3 stages together produce 30 to 38 
.The net reaction for the 8 proper steps of the cycle:
DGº' = -49 kJ/mol DG ~ -115 kJ/mol
See also
It is the final common catabolic pathway for the oxidation of fuel molecules. Two carbons enter the citric acid cycle as
and two carbons leave as
. In the course of the cycle, four oxidation-reduction reactions take place to yield reduction potential in the form of three molecules of and one molecule of . A high energy phosphate bond (GTP) is also formedImages:
Citric acid cycle
Pyruvate Dehydrogenase Complex
Structure of the thiamin diphosphate dependent enzyme pyruvate decarboxylase
(the E1 part of the complex)
(1pyd.pdb)
Pyruvate Dehydrogenase Complex
The lipoyl E2 domain of complex which serves as an acyltransferase.
(1iyu.pdb)
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