1. Cellular Respiration
Ms. Lowrie
Biology 11

2. Energy Transformation
Chemical energy in food converted into energy that cells can use
Glucose to ATP
Occurs in plants and animals

3. Figure 3 (pg 60)
Photosynthesis
Cellular
Respiration

4. Compare the Equations Photosynthesis Cellular Respiration Light energy
Carbon
dioxide
Water
Glucose
Oxygen
Photosynthesis
Glucose
Oxygen
Carbon
dioxide
Energy
Water +
Cellular Respiration

5. The Exchange of Chemicals
Heat
Sunlight
Cellular
respiration
Photosynthesis
Note: Products from one process are reactants for the other.

6. Cellular Respiration & Breathing
Exchanges these gases between blood and outside air
Cellular respiration
Requires cells to exchange gases with surroundings
Lungs
Muscle
cells
Cellular
respiration

7. Remember … Why does energy need to be transferred from glucose to ATP?
Glucose has TOO much energy
Therefore, unusable
ATP – usable energy for cell

8. Cellular Respiration Summary Equation Glucose Oxygen Carbon dioxide
Energy
Water +
Water

9. Occurs in mitochondria
Three Steps
Glycolysis
Occurs in cytoplasm
Kreb’s cycle
Electron transport
system
Can occur with oxygen (aerobic) or without oxygen (anaerobic)
Occurs in mitochondria

10. Cytoplasm
(cytosol)
Mitochondrion
Glycolysis
Krebs
Cycle
Electron
Transport

11. Step 1 – Glycolysis Location: Does NOT require oxygen
Cytoplasm
Does NOT require
oxygen
Anaerobic phase
Plants -> Bacteria -> Humans!

12. Glycolysis Glucose is broken down into 2 PGAL
Uses 2 ATP molecules
Each PGAL is converted into pyruvate
a.k.a. pyruvic acid
pyruvate
PGAL
glucose
PGAL
pyruvate

13. Glycolysis – Glucose Breakdown

14. Glycolysis 2 NAD+ (hydrogen carrier) gain hydrogen & electrons
Creates 2 NADH
4 ATP are produced
2 ATP replace those used to initiate
Net gain of 2 ATP molecules

15. 2 Pyruvic acid
Glucose

16. Cytoplasm
NADH
Glycolysis 2
Pyruvate
Glucose

17. Kreb’s Cycle & Electron Transport System
Location:
Mitochondria
DO require oxygen
Aerobic

18. Step 2 – Kreb’s Cycle (Citric Acid Cycle)
Pyruvate changed into usable form
Acetyl coenzyme A (coA)
CoA 2 1
Acetic
acid 3
Pyruvic
acid
Acetyl-CoA
(acetyl-coenzyme A)
CO2
Coenzyme A

19. What do we do with: the C, H and O?
Kreb’s Cycle
Acetyl-coA goes through a series of reactions with water
Uses water from atmosphere
Then enters Kreb’s Cycle
Glucose (C6H12O6) finishes breaking down
What do we do with: the C, H and O?

20. Kreb’s Cycle Carbon & Oxygen create CO2 Hydrogen & electrons
Which is released to atmosphere
Hydrogen & electrons
Picked up by NAD+ or FAD (hydrogen receptors) to form NADH or FADH2
Net gain is 2 ATP
1 from each pyruvate

21. Cycle Repeats Twice Krebs Cycle Input Output Acetyl coA 3 CO2 ADP
3 NAD
FAD
Cycle Repeats Twice

22. Cytoplasm
Mitochondria
NADH
NADH & FADH2
2 Acetyl
coA
Glycolysis 2
Pyruvate
Krebs
Cycle
Glucose

23. Step 3 – Electron Transport System
Uses hydrogen from NADH & FADH2
Hydrogen (and its electrons) are passed down a “stairway” of reactions
Energy is released with each step

24. Electron Transport System
Oxygen = final hydrogen electron acceptor
“Catches” hydrogen
Combines with two hydrogen
Forms water
Net gain is 34 ATP

25. Electron Stairway Hydrogen electrons “falling”
1/2
(from food via NADH)
Energy for
synthesis of
Hydrogen electrons “falling”
Creates energy at each step
2 H
2 e
Electron transport chain
2 e
1/2
2 H

26. Cytoplasm
Mitochondria
NADH
NADH & FADH2
2 Acetyl
coA
Glycolysis 2
Pyruvate
Krebs
Cycle
Electron
Transport
Glucose

27. Adding Up Aerobic ATP Glycolysis 2 ATP Kreb’s + 2 ATP
Electron Transport + 34 ATP
38 ATP

28. Adding Up Aerobic ATP Cytoplasm Mitochondria Glycolysis 2 Acetyl- CoA
Pyruvate
Krebs
Cycle
Electron
Transport
Glucose
Maximum
per
glucose:

29. Summary Equation +
Glucose
Oxygen
Water
Carbon
dioxide
Water
Energy

30. Balanced Equation – Note Water
Glucose
Oxygen
Water
Energy

31. Task – Electron Transport System
Use notes & pages 62 & 63
Answer:
#3, 4
(page 64)

32. #3 – Electron Transport System
Series of hydrogen (electron) acceptors
As hydrogen moves, energy is released
What if energy from glucose was released all at once?
Too quick
Cause cell damage

33. #4 – Energy in Electron Transport
Results in:
34 ATP
Water

34. The process of mitochondria breaking down glucose to produce ATP is …
Photosynthesis
Cellular respiration
Glycolysis
Calvin cycle

35. The stages, in order, of cellular respiration are …
Carbon fixation, Calvin cycle, Citric acid cycle
Light reactions, Kreb’s cycle, Electron transport system
Glycolysis, Kreb’s cycle, Electron transport system
Citric acid cycle, Glycolysis, Electron transport system