CO 2 are released in the citric acid cycle (see Figure 9.2)? A) 2 B) 4 C) 6 D) 12 E) 3. 49) If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in Figure 9.2? A) There will be no change in the levels of oxaloacetate and citric acid.
The citric acid cycle was first postulated as the pathway of pyruvate oxidation in animal tissues by Hans Krebs, in 1937. The idea of the cycle came to him during a study of the effect of the anions of various organic acids on the rate of oxygen consumption during pyruvate oxidation by suspensions of minced pigeon-breast muscle.