1. Creating more electron carriers
Kreb’s Cycle
Creating more electron carriers

2. Overivew TODAY’S GOALS:
Review big steps of aerobic cellular respiration
Take a look at mitochondrion structure
Kreb’s cycle key ideas

3. Cellular Respiration

4. Cellular Respiration Phases of aerobic cellular respiration
Glycolysis (the beginning of all cellular respiration)
Transition / Link / Acetyl-CoA reaction
Krebs cycle
Electron transport system
These phases are nothing more than metabolic reactions involving the conversion of glucose & other molecules into carbon dioxide & water
The resulting energy released from this conversion is used to produce ATP

5. Cellular Respiration
Act it out!

6. Cellular Respiration

7. Cellular Respiration Mitochondria structure
Similar in arrangement to the chloroplast
It is a double membrane organelle
The intermembrane space is bounded by the outer membrane & the inner membrane
The inner membrane encloses a central space called the matrix. The transition reaction & Krebs cycle occur within matrix.
The inner membrane is folded into cristae. The electron transport system is located in the inner membrane or cristae.

8. Cellular Respiration

9. TEM of a Mitochondrion a. c. b.

10. Cellular Respiration Transition, Link, or Acetyl-CoA reaction
Occurs in the matrix of the mitochondrion
Purpose: Creation of acetyl CoA for Kreb’s cycle; creation of reduced electron carriers (NADH)
Reactants = 2 pyruvates, 2 co-enzyme A (CoA), 2 NAD+
Products = 2 acetyl CoA, 2 NADH + H+, 2 CO2

11. Cellular Respiration

12. Cellular Respiration Krebs Cycle
Occurs in the matrix of the mitochoncrion
Reactants = 2 acetyl CoA (from? __________), 2 ADP, 2 Pi, 6 NAD+, 2 FAD
Products = 2 ATP, 6 NADH, 2 FADH2, 4 CO2
FAD – flavin adenine dinucleotide – an electron carrier similar to NAD+
During Krebs cycle both NAD+ & FAD are reduced to NADH & FADH2 respectively
If both of these molecules are being reduced, what has to be happening to other molecules?

14. Kreb’s Cycle
Acetyl-CoA feeds the two carbons it got from pyruvate (during the link reaction) into the cycle.
NADH, FADH2, a little ATP, and CO2 are generated.

15. Fill in the blanks