The Krebs cycle occurs in the mitochondria and involves 8 steps to completely oxidize acetyl groups derived from pyruvate. During each turn of the cycle, acetyl CoA adds to oxaloacetate to form citrate. As citrate is further modified, carbon dioxide is released and NADH, FADH2, and ATP are generated. One turn of the Krebs cycle results in the production of 3 NADH molecules, 1 ATP, and 1 FADH2.

1. Krebs Cycle

2. How well do
you know
the Krebs
cycle?
Let me
explain
these
steps.

3. In cellular respiration 2 pyruvate are created but
only 1 is needed to go through the Krebs cycle,
thus it goes around twice so remember what
you end up with it doubled.
Takes place in the mitochondria.

4. • 1) Acetyl CoA adds two carbon fragment so
that it can oxaloacetate to make citrate.

5. • 2) Citrate is converted to isocitrate by
removing one water molecule to add another.

6. • 3) citrate loses a CO2 molecule, where the
resulting compound would than be oxidized
making NAD to NADH. Making 1 NADH.

7. • 4) Another CO2 is lost which than cause NAD
to become NADH, than the left over molecule
attaches to coenzyme A, but is unstable.
Making 1 NADH.

8. • 5) CoA is than displaced by a phosphate
group which is formed into GDP, which makes
GTP, than ADP, which formed ATP. Making 1
ATP.

9. • 6) 2 hydrogen's are transformed into FAD to
form FADH2. producing 1 FADH2.

10. • 7) the addition of water molecules cause the
bonds in substrate to rearrange.

11. • 8) The substrate is than oxidized making NAD
to NADH, than regenerating oxaloacetate.
Making 1 NADH.

12. Results
• 3 NADH
• 1 ATP
• 1 FADH