1. Cell Energy: Cellular Respiration

3. Cellular Respiration Overview
Cytoplasm
Mitochondria
Electrons
[Inner membrane]
Glycolysis
Krebs Cycle
Electron Transport Chain (ETC)
[Matrix]
Glucose
Pyruvate
34 ATP
2 ATP
Image modified from—Campbell Biology: Concepts and Connections, 5th ed. (Online textbook). Retrieved 30 March 2010 from:

4. Comparing photosynthesis and cell respiration
The energy flow in these reactions take place in opposite directions
The equation for photosynthesis and cellular respiration are the reverse of each other
Photosynthesis releases oxygen and cellular respiration uses the oxygen to release the energy in food
Photosynthesis uses carbon dioxide and cellular respiration replaces it.
Photosynthesis: Chloroplast
Cellular Respiration: Mitochondria

6. Draw in your notes

7. Cellular respiration overview
Goal: Convert food (C6H12O6) into energy  ATP
Overall Reaction:
C6H12O  6 CO2 +6 H20 + ENERGY (ATP)
In the presence of oxygen: Aerobic ATP
Glycolysis
Krebs cycle
ETC
Without oxygen- Anaerobic- 2 ATP
Fermentation: Alcoholic and Lactic Acid

8. Big Picture GLUCOSE Glycolysis Not a lot of ATP made Then With oxygen
Aerobic Respiration
Without oxygen
Fermentation
Alcoholic
Lactic Acid
Glycolysis
Not a lot of ATP made

9. Glycolysis- the first step in releasing energy
Only a small amount of energy is released in this step (2 ATP)
Happens first whether oxygen is present or not
Location: In the cytoplasm of the cell (not yet in the mitochondria)
Reactants: Glucose
Products:
2 Pyruvate
2 NADH (NAD+, Electrons, and Hydrogen) as an electron carrier
4 ATP are made – 2 ATP are used = 2ATP

11. Cellular Respiration Overview
Cytoplasm
Mitochondria
Electrons
[Inner membrane]
Glycolysis
Krebs Cycle
Electron Transport Chain (ETC)
[Matrix]
Glucose
Pyruvate
34 ATP
2 ATP
Image modified from—Campbell Biology: Concepts and Connections, 5th ed. (Online textbook). Retrieved 30 March 2010 from:

12. In the presence of oxygen the cycle will continue into the mitochondria!

13. Krebs Cycle
Named after Hans Krebs- Also known as the Citric Acid Cycle
Pyruvate is broken down into Carbon Dioxide in a series of energy extracting reactions
Takes place in the matrix or space in the mitochondria
Reactants: Pyruvate (3 carbon sugar) and oxygen
Products: CO2, NADH, FADH2 (from FAD+), and 2 ATP
One carbon from the Pyruvate attaches to an O2 molecule: CO2
The remaining carbons go through a series of events to release more CO2 and add electrons to NAD+  NADPH, and FAD+  FADH2 to fuel the next cycle

14. Image taken from www.sp.uconn.edu
Chemically,
this is how
it all goes down.
Image taken from

15. Cellular Respiration Overview
Cytoplasm
Mitochondria
Electrons
[Inner membrane]
Glycolysis
Krebs Cycle
Electron Transport Chain (ETC)
[Matrix]
Glucose
Pyruvate
34 ATP
2 ATP
Image modified from—Campbell Biology: Concepts and Connections, 5th ed. (Online textbook). Retrieved 30 March 2010 from:

16. Electron Transport Chain (ETC)
Takes place on the Cristae of the mitochondria
The electron carriers FADH2 and NADH take the high energy electrons from the Krebs Cycle to the electron transport chain to convert ADP into ATP
As electrons are passed from carrier to carrier, the energy is used to pump hydrogen ions (H+) across the membrane of the mitochondria.
This high concentration of H+ flow through a protein, ATP Synthase, to convert ADP into ATP
Forming 34 ATP
Since oxygen is present, some of it will attach to the H+  H20

18. Cellular Respiration Overview
Cytoplasm
Mitochondria
Electrons
[Inner membrane]
Glycolysis
Krebs Cycle
Electron Transport Chain (ETC)
[Matrix]
Glucose
Pyruvate
34 ATP
2 ATP
Image modified from—Campbell Biology: Concepts and Connections, 5th ed. (Online textbook). Retrieved 30 March 2010 from:

19. Anaerobic conditions lead to . . . Fermentation
What if after glycolysis, there is NO oxygen????
Anaerobic conditions lead to
Fermentation
1. Alcoholic
2. Lactic Acid
***No more ATP produced after glycolysis

20. Summary

21. Photosynthesis and Cellular Respiration “Cycle”
Products of one become reactants of the other!