1. Cellular Respiration

2. CELLULAR RESPIRATION C6H12O6 + 6O2  6CO2 + 6H2O + energy
Catabolic (breaking down molecules),
Exergonic (energy producing),
oxygen (O2) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H2O).
In other words, cells transfer energy from food molecules to STP, the byproduct is water and carbon dioxide
C6H12O6 + 6O2  6CO2 + 6H2O + energy
glucose
ATP

3. In what kinds organisms does cellular respiration take place?
Question:
In what kinds organisms does cellular respiration take place?

4. Plants and Animals Plants - Autotrophs: self-producers.
Animals - Heterotrophs: consumers.

5. Mitochondria Organelle where cellular respiration takes place. Inner
membrane space
Matrix
Cristae
Outer
membrane
Inner
membrane

6. THE BIG PICTURE
The Big Picture

7. BREAKDOWN OF CELLULAR RESPIRATION
Four main parts (reactions).
1. Glycolysis (splitting of sugar)
a. Cytosol (cytoplasm), just outside of mitochondria.
2. Grooming Phase
a. migration from cytosol to matrix.

8. BREAKDOWN OF CELLULAR RESPIRATION
3. Krebs Cycle (Citric Acid Cycle)
a. mitochondrial matrix
4. Electron Transport Chain (ETC) and
Oxidative Phosphorylation
a. Also called Chemiosmosis
b. inner mitochondrial membrane.

9. 1. GLYCOLYSIS Means “splitting glucose”.
Glucose is broken down into 2 pyruvate molecules.
Occurs in the cytoplasm (cytosol) just outside of mitochondria.
It is anaerobic which means it does NOT require oxygen.
YEILDS: 2 ATP, 2 NADPH, 2 pyruvate

10. 1. GLYCOLYSIS
TAKE NOTE:
In all cells, all of the main energy releasing pathways start with the same reactions in the cytoplasm/cytosol.

11. 1. GLYCOLYSIS Two phases (10 steps): A. Energy investment phase
a. Preparatory phase (first 5 steps).
B. Energy yielding phase
a. Energy payoff phase (second 5 steps).

12. 1. GLYCOLYSIS A. Energy Investment Phase: C-C-C-C-C-C C-C-C
Glucose (6C)
Glyceraldehyde phosphate (2 - 3C)
(G3P or GAP)
2 ATP used
0 ATP produced
0 NADH - produced
2ATP
2ADP + P

13. 1. GLYCOLYSIS B. Energy Yielding Phase
Glyceraldehyde phosphate (2 - 3C)
(G3P or GAP)
Pyruvate (2 - 3C)
(PYR)
0 ATP used
4 ATP produced
2 NADH - produced
4ATP
4ADP + P
C-C-C C-C-C
GAP
(PYR)

14. 1. GLYCOLYSIS Total Net Yield 2 - 3C-Pyruvate (PYR)
2 - ATP (Substrate-level Phosphorylation)
2 – NADH
(4 ATP are made, but two are used to get the process started so the net ATP is 2.)

15. SUBSTRATE-LEVEL PHOSPHORYLATION
ATP is formed when an enzyme transfers a phosphate group from a substrate to ADP.
Enzyme
Substrate O-
C=O
C-O-
CH2 P
Adenosine
ADP
(PEP)
Example:
PEP to PYR P
ATP O-
C=O
CH2
Product
(Pyruvate)
Adenosine

16. 1. GLYCOLYSIS
Glycolysis

17. FERMENTATION Called anaerobic.
Occurs in cytoplasm when cells are deprived of oxygen.
Lactic acid forms during increased muscle activity. Cramps result from increased acidity level.
Alcohol fermentation occurs in fungi such as yeast and some bacteria produce ethanol and CO2.

18. FERMENTATION Remember: glycolysis is part of fermentation. Two Types:
1. Alcohol Fermentation
2. Lactic Acid Fermentation

19. ALCOHOL FERMENTATION Plants and Fungi  beer and wine 2ATP C P 2NADH C
glucose
Glycolysis C
C C
2 Pyruvic
acid
2ATP
2ADP
+ 2
2NADH P
2 NAD+ C
2 Ethanol
2CO2
released
2NADH
2 NAD+

20. ALCOHOL FERMENTATION End Products: Alcohol fermentation
2 - ATP (substrate-level phosphorylation)
2 - CO2
2 - Ethanols

21. LACTIC ACID FERMENTATION
Animals (pain in muscle after a workout).
Glucose
Glycolysis C
2 Pyruvic
acid
2ATP
2ADP
+ 2
2NADH P
2 NAD+
C C
2 Lactic
acid
2NADH
2 NAD+ C

22. LACTIC ACID FERMENTATION
End Products: Lactic acid fermentation
2 - ATP (substrate-level phosphorylation)
2 - Lactic Acids

23. 2. GROOMING PHASE Occurs when Oxygen is present (aerobic).
2 Pyruvate (3C) molecules are transported through the mitochondria membrane to the matrix and is converted to 2 Acetyl CoA (2C) molecules.
Cytosol C
2 Pyruvate
2 CO2
2 Acetyl CoA
C-C
2NADH
2 NAD+
Matrix

24. 2. GROOMING PHASE End Products: grooming phase 2 - NADH 2 - CO2
2- Acetyl CoA (2C)

25. 3. KREBS CYCLE (CITRIC ACID CYCLE)
Aerobic which means it requires O2.
Each Acetyl-CoA enters the Krebs Cycle resulting in two complete cycles to get yield.

26. 3. KREBS CYCLE (CITRIC ACID CYCLE)
Location: mitochondrial matrix.
Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citrate (6C).
It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule.
Mitochondrial
Matrix

27. 3. KREBS CYCLE (CITRIC ACID CYCLE)
1 Acetyl CoA (2C)
3 NAD+
3 NADH
FAD
FADH2
ATP
ADP + P
(one turn)
OAA (4C)
Citrate (6C)
2 CO2

28. 3. KREBS CYCLE (CITRIC ACID CYCLE)
2 Acetyl CoA (2C)
6 NAD+
6 NADH
2 FAD
2 FADH2
2 ATP
2 ADP + P
(second turn)
OAA (4C)
Citrate (6C)
4 CO2

29. 3. KREBS CYCLE (CITRIC ACID CYCLE)
Total net yield (2 turns of krebs cycle)
ATP (substrate-level phosphorylation)
2. 6 – NADH 
FADH2
CO2
**Your notes say 8 because they are counting the two from the Grooming phase.

30. 3. KREBS CYCLE
Krebs Cycle

31. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
Aerobic
Occurs in the cristae of the mitochondria.
Electron acceptors in the chain accept NADH/FADH2 electrons. As electrons pass down a series of molecules to O2 – the O2 combines with H atoms to form H2O and ATP.

32. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
Location: inner mitochondrial membrane.
Uses ETC (cytochrome proteins) and ATP Synthase (enzyme) to make ATP.
ETC pumps H+ (protons) across inner membrane (lowers pH in inner membrane space).
Inner
Mitochondrial
Membrane

33. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
The H+ then move via diffusion (Proton Motive Force) through ATP Synthase to make ATP.
All NADH and FADH2 converted to ATP during this stage of cellular respiration.
Each NADH converts to 3 ATP.
Each FADH2 converts to 2 ATP (enters the ETC at a lower level than NADH).

34. 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
Inner
membrane space
Matrix
Cristae
Outer
membrane
Inner
membrane

35. 4. ETC and Oxidative Phosphorylation (Chemiosmosis for NADH)
ATP
Synthase
1H+
2H+
3H+
higher H+
concentration H+
ADP +
lower H+
(Proton Pumping) P E T C
NAD+
2H+ + 1/2O2
H2O
Intermembrane Space
Matrix
Inner
Mitochondrial
Membrane

36. 4. ETC and Oxidative Phosphorylation (Chemiosmosis for FADH2)
ATP
Synthase
1H+
2H+
higher H+
concentration H+
ADP +
lower H+
(Proton Pumping) P E T C
FAD+
2H+ +
1/2O2
H2O
Intermembrane Space
Matrix
Inner
Mitochondrial
Membrane

37. Electron Transport Chain
4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)
YEILD:
10 NADH converts to 30 ATP
2 FADH2 converts to 4 ATP
Remember FADH produces 2 ATP and NADH produces 3 ATP.
Electron Transport Chain

38. ATP NET ATP YIELD 04 ATP - substrate-level phosphorylation
02 ATP – Krebs Cycle
32 ATP - ETC & oxidative phosphorylation
38 ATP – TOTAL
-02 ATP used in glycolysis
36 ATP – NET TOTAL YIELD
ATP

39. EUKARYOTES Total ATP Yield
02 ATP - glycolysis (substrate-level phosphorylation)
04 ATP - converted from 2 NADH - glycolysis
06 ATP - converted from 2 NADH - grooming phase
02 ATP - Krebs cycle (substrate-level phosphorylation)
18 ATP - converted from 6 NADH - Krebs cycle
04 ATP - converted from 2 FADH2 - Krebs cycle
36 ATP - TOTAL
All from one glucose molecule!

40. MAX ATP YIELD FOR CELLULAR RESPIRATION (EUKARYOTES)
Glucose
Glycolysis
2ATP ATP 6ATP 18ATP ATP ATP
2 ATP
(substrate-level
phosphorylation)
2NADH
6NADH
Krebs
Cycle
2FADH2
2 Pyruvate
2 Acetyl CoA
ETC and Oxidative
Phosphorylation
Cytosol
Mitochondria
36 ATP (maximum per glucose)

41. PROKARYOTES Total ATP Yield
02 ATP - glycolysis (substrate-level phosphorylation)
06 ATP - converted from 2 NADH - glycolysis
06 ATP - converted from 2 NADH - grooming phase
02 ATP - Krebs cycle (substrate-level phosphorylation)
18 ATP - converted from 6 NADH - Krebs cycle
04 ATP - converted from 2 FADH2 - Krebs cycle
38 ATP - TOTAL

42. QUESTION:
In addition to glucose, what other various food molecules are use in Cellular Respiration?

43. CATABOLISM OF VARIOUS FOOD MOLECULES
Other organic molecules used for fuel.
Carbohydrates: polysaccharides
Fats: glycerol’s and fatty acids (during starvation, fasting, untreated diabetes)
Proteins: amino acids (if there are excess proteins or not fats or sugars.)