1. 5.5 The Krebs Cycle

2. 5.5 The Krebs Cycle “GROOMING”
Pyruvate from Glycolysis is transported into the mitochondria.
A CO2 is removed, resulting in a 2-carbon molecule, acetate (or acetic acid).
NAD+ is reduced to NADH, and Coenzyme A (CoA) bonds to acetate to form Acetyl CoA.

3. 5.5 The Krebs Cycle “GROOMING”
Happens in between Glycolysis & Kreb’s Cycle (mitochondria)
Coenzyme A = a carrier molecule; brings acetate into cycle
Produces 1 CO2 & 1 NADH

4. 5.5 The Krebs Cycle
1. Acetyl CoA combines the with a 4-C acid (oxaloacetate) to form a 6-C citrate.
CoA is released & recycled to carry more acetate.

5. 5.5 The Krebs Cycle
2. A carbon atom from citrate is oxidized and released as CO2; NAD+ is reduced to NADH, & a 5-C sugar, ketoglutarate results.

6. 5.5 The Krebs Cycle
3. A carbon atom from ketoglutarate is oxidized and released as CO2, another molecule of NAD+ is reduced to NADH, & 4-carbon sugar results.

7. 5.5 The Krebs Cycle
4. The 4-C molecule is rearranged & oxidized, which reduces an NAD+ to NADH, an FAD to FADH2, and creates a molecule of ATP. This forms oxaloacetate (which starts the cycle).

9. Summary of Glycolysis & Krebs Cycle
Products
Location
Raw Materials
ATP
NADH
FADH2
Other
Glycolysis
Cytoplasm
Glucose 2
2 Pyruvates
"Grooming"
Mitochondria
Pyruvate
2 Acetyl CoA
2 Carbon dioxide
Krebs Cycle
Mitochondrial Matrix
Acetyl CoA (also will need oxygen) 6
4 Carbon Dioxide