1. Cellular Respiration

2. Cellular Respiration
The process by which the mitochondria breaks down glucose to produce ATP is called cellular respiration.
C6H12O6 + 6O2  6CO2 + 6H2O + Energy

3. How much energy is actually present in food?
Cellular Respiration
How much energy is actually present in food?
1 gram of sugar glucose, when burned in the presence of oxygen, releases 3811 calories of heat energy!

4. “C” or Calorie used on food labels = 1000 calories (kilocalorie)
Cellular Respiration
calorie- the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius.
“C” or Calorie used on food labels = 1000 calories (kilocalorie)

5. Cellular Respiration
Cells release the energy from glucose and other food components (they don’t burn it)

6. Cellular Respiration
When the body has oxygen, aerobic respiration can take place and produce 36 ATP molecules.
There are 3 stages of aerobic respiration:
Glycolysis
Krebs cycle (aka Citric Acid Cycle)
Electron transport chain

7. THE BIG PICTURE

8. Glycolysis
Glycolysis takes place in the cytoplasm of the cell.

9. Glycolysis
Glycolysis is the process where glucose is broken down in 2 pyruvic acid molecules. Pyruvic acid is a 3 carbon molecule.
The net gain of ATP molecules in glycolysis is 2 ATP molecules. 4 -2 2

10. Glycolysis
Following glycolysis, the pyruvic acid moves into the mitochondria.

11. The Krebs Cycle Citric Acid Cycle
AKA
Citric Acid Cycle
The Krebs cycle takes place in the MATRIX!
Pyruvic acid enters the Krebs cycle and becomes broken down. As this occurs, 2 carbon dioxide molecules are released.
In addition, 2 ATP molecules are released.
Electron carriers such as FAD and NAD are used to pick up energized electrons and pass them to the ETC.

12. The Krebs Cycle
AKA
Citric Acid Cycle

14. Krebs Cycle 2 ATP NADH + H pyruvic acid FADH2 ADP NAD CO2 FAD
Electron carriers
NAD
NADH + H
pyruvic
acid
FAD
FADH2
CO2
FYI: Flavin adenine dinucleotide Nicotinamide adenine dinucleotide

15. The Electron Transport Chain
The last step of respiration is the electron transport chain or ETC.
It takes place in the inner membrane.
In the presence of oxygen, the electron transport chain will produce 32 ATP molecules and water.
The total of ATP molecules released from AEROBIC respiration is 36. 36 36 36 36

16. Electron Transport Chain
Electron carriers NADH and FADH2 release the Hydrogen ions across the membrane. This creates a concentration gradient.
When oxygen enters the ETC, it becomes the final electron acceptor of the Hydrogens and creates H2O.
As the hydrogen ions come back across the membrane, ADP is converted into ATP.
Animation:

17. Electron Transport Chain
Electron carriers NADH and FADH release the Hydrogen ions to proteins to cross the membrane. This creates a concentration gradient.
When oxygen enters the ETC, it becomes the final electron acceptor of the Hydrogen ions and creates H2O.
As the hydrogen ions come back across the membrane, ADP is converted into ATP.

18. THE BIG PICTURE

19. Cellular respiration

20. Anaerobic Resp Fermentation
AKA
Fermentation
There are times when cells are without oxygen for a short period of time. When this happens, anaerobic respiration is taking place.
In anaerobic respiration, glycolysis takes place; then followed by one of two pathways:
Lactic Acid Fermentation or Alcoholic Fermentation.
Total ATP molecules released = 2.

21. Aerobic: presence of oxygen Anaerobic: absence of oxygen
respiration
Aerobic

22. Types of Anaerobic Respiration
When our cells run out of oxygen and begin fermentation, we build up lactic acid. That lactic acid build up in the muscle makes us feel a cramp and burning sensation.
C6H12O6  ATP + lactic acid
Lactic Acid Fermentation

23. fermentation

24. Types of Anaerobic Respiration
Some fungi also undergo fermentation. They release ethyl alcohol and carbon dioxide.
C6H12O6  ATP + CO2 + ethyl alcohol
This process is key for the yeast that create wine and other alcoholic beverages.
Alcoholic Fermentation

25. Types of Anaerobic Respiration
Yeast undergo this type of fermentation when making bread.

26. fermentation

27. Comparing Photosynthesis and Respiration
Glucose made
Light energy required
ATP broken down in 2nd phase of p.s.
CO2 taken in
O2 released
Needs water
Takes place in chloroplast
Takes place in autotrophs
Glucose broken down
Light is not required
Energy created in ATP
CO2 released
O2 taken in
Water released
Takes place in mitochondria
Takes place in all organisms
Require use of ATP molecules
Take place in plants
Necessary to sustain all life on earth