1. Stage 3: Kreb’s Cycle

2. Kreb’s Cycle 8 step process
Each step is catalyzed by a specific enzyme
It is a cyclic process because you start and end with oxaloacetate

3. 1 8 2 3 7
CoA 6
+Pi 4 5

4. GDP + Pi
GTP
ATP
ADP

5. Overall Equation
Oxaloacetate + acetyl CoA + ADP + Pi + 3NAD+ + FAD +H2O
CoA + ATP + 3NADH + FADH2 + 2CO2 + oxaloacetate
TIMES TWO!!!!

6. By the end of this cycle, the original molecule is entirely consumed
The 6 carbon atoms leave the process as CO2
All that is preserved of the original glucose molecule is most of its energy, which is stored in the form of:
4 ATP (2 from glycolysis and 2 from Kreb’s)
10 NADH (2 from glycolysis, 2 from pyruvate oxidation, 6 from Kreb’s)
2 FADH2 (from Kreb’s)
Most of the energy stored in NADH and FADH2 will eventually be transferred to ATP in the last stage of respiration

7. Homework
Section 4.2 p
Complete questions