Steps in the cycle

Steps in the cycle - and the cycle is back to oxaloacetic...

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Steps in the cycle Preparation of pyruvate . The pyruvate produced in glycolysis is transported to the matrix of the  mitochondria where it is converted to acetyl-CoA, a three-step conversion.  The two 3-carbon pyruvate molecules are oxidized to two 2-carbon acetyl groups  (CH 3 CO).  Two molecules of CO 2  are released.  Two molecules of NADH are formed. The acetyl groups are then attached to molecules of coenzyme A, forming acetyl-CoA, and the cycle  begins. Cyclical reactions . Acetyl-CoA, the substrate starting point, releases its 2-carbon portion to the 4- carbon organic acid, oxaloacetic acid, making the 6-carbon citric acid. The seven steps are repeated 
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Unformatted text preview: and the cycle is back to oxaloacetic acid—in the process having lost two carbon molecules to two molecules of CO 2 and releasing electrons to the high-energy compounds NADH, ATP, and FADH. Two turns of the cycle are necessary to release the six carbons of the original glucose molecule. The energy input into the Krebs cycle comes from the oxidation (i.e. the removal of electrons) of NADH and FADH 2 and their regeneration back to NAD + and FAD. Without a constant supply of the latter compounds, the Krebs cycle stops....
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.

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