1. ADP, ATP and Cellular Respiration

2. Summary of cellular respiration
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3. What Is ATP? Adenosine Triphosphate
Energy used by all Cells for:
- anabolic reaction
- cell growth
- tissue repair
- movement
- reproduction
- active transport
- active secretion
Adenosine Triphosphate
Organic molecule containing high-energy Phosphate bonds

4. Chemical Structure of ATP
Adenine Base
3 Phosphates
Ribose Sugar

5. How Do We Get Energy From ATP?
By breaking the high- energy bonds between the last two phosphates in ATP making ADP.

6. How is ATP Re-Made? Another Enzyme is used! ATP ADP +Pi + energy
The reverse of the previous process occurs.
Another Enzyme is used!
ATP Synthetase
ATP ADP +Pi + energy

7. The ADP-ATP Cycle ATP Synthetase ATP-ase
(enzyme that breaks ADP to ATP)
ATP-ase
(Enzyme that breaks ATP to ADP)
The creation and usage of ATP and ADP goes in a continuous cycle. ATP-ase is breaking the bonds between the second and third phosphate groups in ATP, releasing energy. That phosphate then makes its way to be connected to another ADP with the help of ATP Synthetase, using up energy to build the bonds back up.

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9. Glucose
The source of energy for cellular metabolism in all organisms (except archaea)
How is Glucose ‘Energy’
Chemical Energy (energy stored in the molecular bonds)
Bonds break releasing free energy and stable products (exergonic reaction)
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10. When is ATP Made in the Body?
During a Process called Cellular Respiration that takes place in both Plants & Animals

11. Aerobic cellular respiration
C6H12O6 + 6O2 → 6H2O + 6CO2 + 36ATP
This just shows the inputs and outputs. There are about 20 reactions in between
This is referred to as ‘aerobic’ because oxygen is the electron acceptor when electrons are transferred from the glucose molecule
Anaerobic respiration is where electrons from the glucose are transferred to an acceptor molecule other than oxygen
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12. Cellular Respiration Includes pathways that require oxygen
Glucose is oxidized and O2 is reduced
Glucose breakdown is therefore an oxidation-reduction reaction
Breakdown of one glucose results in 36 to 38 ATP molecules

13. What Type of Process is Cellular Respiration?
An Oxidation-Reduction Process or REDOX Reaction
Oxidation of GLUCOSE --> CO2 + H2O (e- removed from C6H12O6)
Reduction  O2  to  H2O (e- passed to O2)
Cellular respiration is what we call an oxidation-reduction reaction because we use a spare electron removed from a glucose molecule and

14. What Carries the Electrons?
NAD+ (nicotinadenine dinucleotide) acts as the energy carrier
NAD+ is a coenzyme
It’s Reduced to NADH when it picks up two electrons and one hydrogen ion

15. Are There Any Other Electron Carriers?
YES! Another Coenzyme!
FAD+ (Flavin adenine dinucleotide)
Reduced to FADH2

16. Other Cellular Respiration Facts
Metabolic Pathway that breaks down carbohydrates
Process is Exergonic as High-energy Glucose is broken into CO2 and H2O
Process is also Catabolic because larger Glucose breaks into smaller molecules

17. What are the Stages of Cellular Respiration?
Glycolysis
The Krebs Cycle
The Electron Transport Chain

18. Where Does Cellular Respiration Take Place?
It actually takes place in two parts of the cell:
Glycolysis occurs in the Cytoplasm
Krebs Cycle & ETC Take place in the Mitochondria

19. Review of Mitochondria Structure
Smooth outer Membrane
Folded inner membrane
Folds called Cristae
Space inside cristae called the Matrix

20. Diagram of the Process Occurs across Cristae Occurs in Cytoplasm
Occurs in Matrix

21. Beginning of Cellular Respiration: Glycolysis
Glycolysis is for both aerobic and anaerobic.
Location: Cytosol
Overall equation for glycolysis:
Glucose  2pyruvate + 2ATP
NOTE there are 10 steps involved in the whole process of glycoslysis (see left) you don’t need to know these
Also produces 2 NADH and 4 ATP
Pyruvate is oxidized to Acetyl CoA and CO2 is removed
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22. Glycolysis Diagram

23. Summary of Glycolysis (you need to know)
Pyruvic acid = pyruvate
For some organisms 2 ATP molecules may be sufficient for energy needs, for others they need to undergo a further biochemical pathway…
ADP
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24. Aerobic cellular respiration
Next step in biochemical pathway: Krebs Cycle
Location: Mitochondria
The 2 pyruvate molecules created in glycolysis enter the mitochondria from the cytoplasm
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25. A Little Krebs Cycle History
Discovered by Hans Krebs in 1937
He received the Nobel Prize in physiology or medicine in 1953 for his discovery
Forced to leave Germany prior to WWII because he was Jewish

26. Krebs Cycle Summary Requires Oxygen (Aerobic)
Cyclical series of oxidation reactions that give off CO2 and produce one ATP per cycle
Turns twice per glucose molecule
Produces two ATP
Takes place in matrix of mitochondria

27. Krebs Cycle
The 2 Pyruvate molecules are transferred into the mitochondria
They undergo a reaction and become a compound: ‘Acetyl CoA’ and CO2
Acetyl CoA enters the Krebs cycle.
Products: CO2 , ATP, loaded acceptor molecules (NADH, FADH2)
Loaded acceptor molecules enter and electron transport system on the inner membrane until they are accepted by oxygen
If there is no oxygen the krebs cycle stops.
The energy released from the electron transport cycle is used to pump H+ from the loaded acceptor molecules into the mitochondrial intermembrane space.
This ion gradient drives the production of ATP
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28. Krebs Cycle Summary
Each turn of the Krebs Cycle also produces 3NADH, 1FADH2, and 2CO2
Therefore, For each Glucose molecule, the Krebs Cycle produces 6NADH, 2FADH2, 4CO2, and 2ATP

29. Krebs Cycle
ATP
NETS: 3NADH, 1ATP, 1FADH2, & 2CO2

30. Electron Transport Chain Summary
34 ATP Produced
H2O Produced
Occurs Across Inner Mitochondrial membrane
Uses coenzymes NAD+ and FAD+ to accept e- from glucose
NADH = 3 ATP’s
FADH2 = 2 ATP’s

31. Anaerobic cellular respiration
No oxygen involved!
Begins with Glycolysis, and continues in the cytoplasm as either
Alcohol fermentation
Lactic acid fermentation
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32. Glucose  ethanol + carbon dioxide + energy
Alcohol Fermentation
C6H12O6 → 2CH3CH2O6H + 2CO2 + 2ATP
Glucose  ethanol + carbon dioxide + energy
Products from glycolysis used are pyruvate, NADH
From the pyruvate molecules, a Carbon dioxide molecule is removed to produce acetaldehyde.
One the NADH molecules donates a H+ to acetaldehyde to from ethanol.
This happens in bacteria and protists, and some plants but alcohol is toxic to plants so they must revert back to aerobic respiration quickly.
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33. Lactic Acid Fermentation
C6H12O6 → 2CH3CH(OH)COOH + 2ATP
Glucose  lactic acid + energy
Anaerobic respiration in animals
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34. Fermentation Occurs when O2 NOT present (anaerobic)
Called Lactic Acid fermentation in muscle cells (makes muscles tired)
Called Alcoholic fermentation in yeast (produces ethanol)
Nets only 2 ATP

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36. Electron Transport Chain Animation