1. Cellular Respiration Notes
Biology - Ms. Spinale

2. Cellular Respiration Video Clip

3. Cellular Respiration:
Energy Transfer
Photosynthesis:
Light Energy → Chemical Energy
Energy + 6CO2 + 6H2O → C6H12O6 + 6O2
Cellular Respiration:
Chemical Energy → Usable Energy → Heat Energy
C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATPs

4. ATP - Adenosine Triphosphate
How our cells get the energy the need to function.
Energy carrier - stores/releases/converts to usable form for cells.
Energy in bonds of phosphates.

5. ADP - Adenosine Diphosphate
Last phosphate breaks free.
Lots of energy is released and used in the cell to do work.
To rebuild energy reserves, the body uses energy from food to put a “P” back onto ADP to reform ATP and the molecule is recycled.

6. ADP - Adenosine Diphosphate
Cycle of bond-breaking and bond-making = storing and releasing.
Breaking bonds takes energy.
Making bonds releases energy.

7. Cellular Respiration
Process by which enzymes convert energy stored in macromolecules (starch/glycogen) or small molecules (glucose) into a usable form of ATP.
Potential energy in food molecules must be converted into a usable form.

8. Begins in the cytoplasm.
Cellular Respiration
Begins in the cytoplasm.
Glycolysis = no O2
Continues in the mitochondria.
Krebs cycle, electron transport system = both with O2

10. Cellular Respiration in 3 Stages: 1 - Glycolysis
Sugar is broken down into 2 pyruvate molecules.
Pyruvate - an organic molecule consisting of a 3-Carbon backbone.
Glyco - sugar; lysis = split.
2 ATP of energy are made.
2 NADH are made and carried away.

11. Cellular Respiration in 3 Stages: 1 - Glycolysis
NADH - a high energy molecule used by cells to generate ATP.

12. Cellular Respiration in 3 Stages: 1 - Glycolysis
The Fate of Pyruvate
Anaerobic respiration - without oxygen.
Fermentation
End of glycolysis - each glucose is broken down into two pyruvates.
No oxygen for aerobic respiration - glycolysis continues.

13. Cellular Respiration in 3 Stages: 1 - Glycolysis
Lactic Acid Fermentation
During exercise, O2 is not supplied fast enough and pyruvic acid is converted to lactic acid.
In muscles, lactic acid builds up and causes eventual fatigue.

14. Cellular Respiration in 3 Stages: 1 - Glycolysis
Lactic Acid Fermentation
After exercise, O2 is still needed to convert lactic acid back into pyruvic acid.
Some organisms get energy from this process; we use lactic acid to make cheese, yogurt, and sour cream.

15. Cellular Respiration in 3 Stages: 1 - Glycolysis
Alcoholic Fermentation
Pyruvic acid is converted into ethyl alcohol and CO2.
Used by yeasts to obtain energy (ATP)
Humans use yeast to make bread and alcoholic beverages.

16. Fermentation Video Clip

17. Cellular Respiration in 3 Stages: 2 - Krebs Cycle
Makes CO2 (carbon dioxide)
2 ATP of energy
10 NADH
Aerobic respiration - requires oxygen
Reactions release most of remaining energy in pyruvate

18. Cellular Respiration in 3 Stages: 2 - Krebs Cycle
Enzymes convert pyruvate into a 2-C molecule by removing a molecule of CO2 - breathe out the waste.

19. Cellular Respiration in 3 Stages: 2 - Krebs Cycle
Acetyl-CoA (from pyruvate) combines with a 4-C molecule.
Forms a 6-C molecule (citric acid).
Broken down to a 5-C molecule, then 4-C molecule.
Releases CO2 at each step.
4-C molecule available to combine with new acetyl-CoA that enters cycle.

21. Krebs Cycle to Electron Transport System
Energy from glucose has been converted to ATP molecules and NADH molecules.
Energy stored in NADH is used to produce large amounts of ATP.
1 NADH = 3 ATP.

22. Cellular Respiration in 3 Stages: 1 - ETS
Final step in aerobic respiration = transfer of electrons.
H atoms (1e-, 1p+) carried by NADH are separated into electrons and protons (H+)
Electrons join with oxygen and protons to form H2O.
Flow of p+ (potential energy) makes ATP.

23. Cellular Respiration in 3 Stages: 1 - ETS
End result = lots of ATP, H2O
34 ATP of energy are made from NADH in the inner membranes of mitochondria.
Molecules of water are made.

25. Anaerobic Respiration
Summary of Products
Aerobic Respiration
Anaerobic Respiration
* Glycolysis
* 2 pyruvate
* 2 ATP
* 2 NADH
* Fermentation
* Lactic acid /
ethyl alcohol

26. Anaerobic Respiration
Summary of Products
Aerobic Respiration
Anaerobic Respiration
* Krebs Cycle
* CO2
* 2 ATP
* 10 NADH

27. Anaerobic Respiration
Summary of Products
Aerobic Respiration
Anaerobic Respiration
* Electron Transport System
* 34 ATP
* H2O

28. What controls how fast sugar is used in the body?
Supply and Demand
What controls how fast sugar is used in the body?
High demand of energy needed:
Sugar is rapidly absorbed from the blood into cells. The liver breaks down glycogen into sugar to restore the blood levels.
Example: exercising

29. Low demand of energy needed:
Supply and Demand
Low demand of energy needed:
Cells use excess sugar to make glycogen in the liver then convert to fat.
Example: resting.

30. Energy Production - ATP: The Ultimate Source
CO2 and H2O are by-products that we release as we exhale.
ATP is the energetic push that starts reactions in the cell.

31. Energy Production - ATP: The Ultimate Source
When the body needs more energy, mitochondria detect increased ADP levels, responding by increasing the rate of respiration.
Presence or absence of oxygen in cells detects fate of pyruvate.

32. Energy Production - ATP: The Ultimate Source
With oxygen: about 38 ATPs per molecule of sugar.
Without oxygen: 2 ATPs are made with alcohol or lactic acid in muscles.