1. How do living things release energy?
Cellular Respiration
How do living things release energy?

2. Aerobic Anaerobic A process that requires oxygen
A process that does not require oxygen

3. Cellular Respiration Equation
Reactants Products
Sugar + Oxygen Carbon Dioxide + water + energy
C₆H₁₂O₆ O₂ CO₂ H₂O energy

4. So What is Cellular Respiration?
The process that releases energy by breaking down food molecules (glucose, etc.) in the presence of Oxygen.
Three main stages:
Glycolysis
Krebs Cycle
Electron Transport Chain

5. What happens if there is no oxygen?
IF there is no oxygen available fermentation happens.
We will come back to this!

6. Fermentation (without oxygen)
Chemical Pathways
Glucose
Krebs cycle
Electron transport
Glycolysis
Alcohol or lactic acid
Fermentation (without oxygen)
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7. Where does all of this happen?
In Both Plant and Animal Cells!!!!
Stage of Respiration
Location
Glycolysis
cytoplasm
Krebs Cycle
mitochondria
Electron Transport Chain

8. Plant and Animal Cell Review
Plant Cell
Mitochondria
Chloroplast
Mitochondria
Mitochondria
Mitochondria
Mitochondria

9. Glycolysis
1 glucose is broken into 2 molecules of pyruvic acid and a small amount of energy.
Requires 2 ATP to get started!
It only releases 4 ATP. This means that the net gain is 2 ATP.
High energy electrons are released and carried to the ETC

10. Krebs Cycle
Pyruvic acid is converted into carbon dioxide in a series of energy extracting reactions.
The pyruvic acid creates 2 more ATP molecules and releases carbon dioxide as waste.
High energy electrons are also released and carried to the electron transport chain.

11. Electron Transport Chain
In the presence of oxygen, the high energy electrons from the Krebs Cycle and Glycolysis are used to turn ADP into ATP.
The chain produces 32 ATP.
Water is given off as waste.

12. Respiration: An Overview
Mitochondrion
Electrons carried in NADH
Pyruvic acid
Electrons carried in NADH and FADH2
Glucose
Krebs Cycle
Electron Transport Chain
Glycolysis
Cytoplasm
Mitochondria 2 2 32
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13. The ATP Totals Stage of Respiration ATP produced Glycolysis
2 ATP (net)
Krebs Cycle
2 ATP
Electron Transport Chain
32 ATP
Total
36 ATP (net)

14. Electron Transport Chain
Flowchart
Cellular Respiration
(C6H1206) +
(02)
Glycolysis
Krebs Cycle
Electron Transport Chain
(CO2) +
(H2O)
Mitochondria
Go to Section:

15. Summary of Cellular Respiration (With Oxygen Present)
Stage
Where
Input
Output
# ofATP
Glycolysis
Cytoplasm
Glucose , 2ATP
Pyruvic Acid, 4ATP, electrons
2 (net)
Krebs Cycle
Mitochondria
Pyruvic Acid, Oxygen
Carbon Dioxide, 2 ATP, electrons 2
ETC
Oxygen, Electrons (carried by NADH and FADH₂)
Water, 32ATP 32

16. What if there is no oxygen? Then Fermentation occurs…..
Fermentation releases the energy in food molecules (glucose) without oxygen.
This process is called anaerobic because it does not require oxygen.
There are two types of fermentation:
Alcoholic Fermentation
Lactic Acid Fermentation

17. Alcoholic Fermentation
Performed by yeasts and a few other microorganisms.
Uses pyruvic acid to regenerate the electron carriers so that glycolysis can continue.
Produces ethyl alcohol and carbon dioxide as waste.

18. Examples of Alcoholic Fermentation
Alcoholic Fermentation occurs in bread dough. When yeast runs out of oxygen they begin to ferment releasing carbon dioxide bubbles. This causes the bread to rise.
Alcoholic Fermentation is also used to make beer and wine.

19. Lactic Acid Fermentation
Performed in the muscle cells of animals.
Turns pyruvic acid into lactic acid and regenerates the electron carriers so that glycolysis can continue.

20. Example of Lactic Acid Fermentation
During rapid intense exercise, your body cannot supply oxygen to your muscles fast enough. This causes the muscles to begin Lactic Acid Fermentation in order to produce ATP.
The lactic acid builds up in your muscles causing you to feel sore.

21. How do you get rid of the Lactic Acid build up?
A chemical pathway that uses extra oxygen will break down the lactic acid.
This is why people breathe heavily after intense exercise. They are basically paying back on oxygen debt.

22. Energy and Exercise Three energy “tanks”:
Stored Energy: a small amount of ATP is stored in cells to support around 6 seconds of intense activity.
Lactic Acid Fermentation: can supply energy for about 90 seconds.
Cellular Respiration: after 90 seconds, this is the only way to obtain continuous ATP. The process is slow. This is why athletes must pace themselves.

23. Summary FermentationType Input Output Takes place In: Alcoholic
Pyruvic Acid
Alcohol, CO2, and electron carriers
Cytoplasm of yeast
Lactic Acid
Lactic Acid and electron carriers
Cytoplasm of muscle cells

24. Cellular Respiration Flipbook Front View (Closed)
Glycolysis
Pay attention to the details…..
Don’t miss anything…..
without oxygen
Fermentation
with oxygen
Stage: 1
End
Stage: 2
Stage: 3
Inside Flipbook (Opened up)
Krebs
Cycle
Electron
Transport
Chain
with oxygen
Glycolysis:
Input:
Output:
Takes Place in:
Fermentation:
Input:
Output:
Takes Place in:
End
(cytoplasm)
Fermentation
Alcohol
Lactic Acid
Back View (Closed)
Without oxygen
Cellular Respiration Equation
(Both Versions)
Reactants Products
(Mitochondria)
Water
Carbon
dioxide
Krebs Cycle:
Input:
Output:
Takes Place in:
Electron Transport Chain:
Input:
Output:
Takes Place in: