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NAD+ reaction. The Kreb Cycle. (named in 1930 after Hans Kreb) Aka citric acid cycle tricarboxylic acid cycle. Product of Glycolysis Pyruvate stores a significant amount of energy - PowerPoint PPT Presentation
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NAD+ reaction
(named in 1930 after Hans Kreb)Aka citric acid cycle tricarboxylic acid cycle
Product of GlycolysisPyruvate stores a significant amount of
energyIf oxygen is present, pyruvate enters the
mitochondria where enzymes complete the oxidation (loss of e-) of organic fuel
Processes involved before the Kreb CyclePyruvate’s carboxyl group is removed
and given off as a molecule of CO2
The remaining two carbon molecules are oxidized (lose e-) to form acetate
The electrons extracted transfer to NAD+ and store energy in the form of NADH Side note: NAD + has been reduced here
Coenzyme A (contains sulfur) attaches to the acetyl group, which is very reactive, and produces acetyl coenzyme A (acetyl CoA)
Processes involved during the Kreb CycleFor each Acetyl CoA that enters the cycle:
Three molecules of NAD+ are reduced to NADH• So six total b/c there are two pyruvates originally
that have been convereted into acetyl CoA Electrons are transferred to FAD (flavin
adenosine dinucleotide-derived from vitamin B) • This reduces FAD to FADH2
• Therefore a total of two molecules of FADH2
One molecule of ATP is produced via substrate phosphorylation• Therefore two ATP total
Three molecules of CO2
• Therefore six total (four during the Kreb Cycle and two when pyruvate was converted to acetate)
Reduced enzymes (carrying a lot of chemical energy), NADH and FADH2, move to the last step of cellular respiration, the electron transport chain (ETC)
kreb cycle animation kreb cycle animation