1. Flow of Energy through the Respiration Process
Cellular Respiration
Flow of Energy through the Respiration Process

2. Review: Producers Producers get their energy from the sun.
Producers convert this light energy into stored chemical energy (glucose).
This process is called photosynthesis.

3. Review: Consumers Consumers get their energy from the producers.
Consumers convert stored chemical energy (glucose) into usable chemical energy (ATP).
This process is called cellular respiration.

4. Energy Storing Molecules
Energy Review
Energy Storing Molecules
ATP, NADPH (NAD+), FADH (FAD+), FADH2
ATP supplies most of the energy that drives metabolism in living things
ATP releases energy when converted into ADP

5. Cellular Respiration Overview
Living things get most of the energy they need from glucose.
Autrotrophs make glucose using photosynthesis
Heterotrophs get glucose from food they eat
Cellular Respiration
The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.

6. Cellular Respiration (aerobic)
Cellular respiration is the process by which glucose (C6H12O6) is broken down to release energy for making ATP, another form of chemical energy.

7. Aerobic Respiration – Equation
C6H12O6 + 6 O H2O + 6 CO ATP
food
(glucose, a carbohydrate)
oxygen
water
carbon
dioxide
Does this look familiar?

8. Cellular Respiration Overview
Cellular Respiration Overall Equation
6O2 + C6H12O6  6CO2 + 6H2O + Energy
Three Stages
Glycolysis
Kreb’s Cycle
Electron Transport Chain
The Main form of Energy produced = ATP

9. Cellular Respiration: An Overview
Mitochondrion
Electrons carried in NADH
Electrons carried in NADH and FADH2
Pyruvic acid
Glucose
Electron Transport Chain
Krebs Cycle
Glycolysis
Mitochondrion
Cytoplasm

10. Diagram Mitochondria In Cytoplasm 2 2 32 Electrons carried in NADH
Electrons carried in NADH and FADH2
Krebs Cycle
Electron Transport Chain
Glucose
Glycolysis 2 2 32

11. Glyco = Glucose lysis = Breakdown Occurs in the cytoplasm of the cell
Glycolysis (1st Stage)
Glyco = Glucose lysis = Breakdown
Occurs in the cytoplasm of the cell
Molecules of GLUCOSE are broken down into 2 molecules of Pyruvic Acid.
Cell must use (invest) 2 ATP
Produces Energy Carrier Molecules
4 ATP
2 NADH

12. To the Electron Transport Chain
Glycolysis (1st Stage)
Glucose
Pyruvic Acid
Pyruvic Acid
To the Electron Transport Chain

13. The “Mighty” Mitochondria
Plant and animal cells contain mitochondria: cell structures that transform chemical energy from glucose to ATP.
The mitochondria is the organelle where the final stages of cellular respiration occurs.
Kreb’s Cycle
Electron Transport Chain
Cells that use a lot of energy have high numbers of mitochondria.
Example: Muscle cells in the heart!!

14. Kreb’s Cycle (2nd Stage)
Aerobic Process = Only if oxygen is present!!
Occurs in the MATRIX of the mitochondria
Pyruvic Acid from Glycolysis enters to form
1 ATP
3 NADH
1 FADH2
CO2 (which is released when we exhale!!)
AKA….Citric Acid Cycle

15. Electron Transport Chain (3rd Stage)
Energy carrier molecules produced during Glycolysis and the Kreb’s Cycle enter the ETC
NADH
FADH2
Occurs in the folds of the Inner Membrane of the Mitochondria
The electrons are passed down a chain of proteins until they reach the final electron acceptor…..oxygen!
So this step is aerobic (requires oxygen)
The ETC produces 32 ATP and H2O

16. Cellular Respiration Flowchart
Inputs st Stage nd Stage rd Stage Outputs
Glucose (C6H1206) +
Oxygen (02)
Glycolysis
Krebs Cycle
Electron Transport Chain
Carbon
Dioxide
(CO2) +
Water
(H2O)

17. BioTheme: Interdependence
BioTheme: Interdependence! Processes are opposites (or compliments of one another)
Photosynthesis:
6 H2O + 6 CO2 + energy (sun) → C6H12O6 + 6 O2
Aerobic Cellular Respiration:
C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy (ATP)

18. Why ATP? An analogy to money…
Glucose in our food is a great source of energy! ($100 bill)
However, individual cell processes may only require a small amount of energy ($1 bill)
Analogy: most vending machines do not accept $100 bills! We need a smaller form of “currency” for these processes.
ATP (adenosine triphosphate) is this important cellular “currency” for life.
ATP releases more appropriate amounts of energy for the individual cellular processes that require energy.

19. Do only animals respire? Or do plants respire too?
The BIG Question is…
Do only animals respire?
Or do plants respire too?
Only plants perform photosynthesis
Plants AND animals perform cellular respiration!
(Can you explain why??)

20. Significant ATP Production
Aerobic cellular respiration releases energy SLOWLY, using oxygen to convert ONE molecule of glucose to 36 ATP!

21. Aerobic Training Ex: long runs, biking, swimming
Can increase the size and number of mitochondria in muscle cells
Can increase the delivery of O2 to muscles by improving the heart and lungs

22. Cellular Respiration (anaerobic)
What happens when cells don’t have enough oxygen?
Some organisms live in an oxygen-free environment. How do they get their energy?

23. Cellular Respiration (anaerobic)
Anaerobic respiration is also called fermentation, or the process by which energy is released from glucose when oxygen is NOT available.
This process allows organisms to continue to produce energy until oxygen is available.
However, this process only releases 2 ATP per molecule of glucose.

24. Anaerobic Training Ex: sprints, strides, quick bursts of energy
Increase the glycogen levels in the muscles
Increase body’s tolerance to lactic acid

25. Minimal ATP Production
In the absence of oxygen, anaerobic respiration only releases 2 ATP for each molecule of glucose broken down.

26. Lactic Acid Fermentation
Anaerobic way of converting energy in animal cells and some microorganisms
Glucose broken down to produce lactic acid, CO2 and energy (ATP)
C6H12O6  lactic acid + CO2 + 2 ATP
EX: muscle cells during strenuous exercise
fermenting cheese, yogurt, sour cream

27. Strenuous Exercise
Lactic acid is produced by your muscle cells during rapid exercise when the body cannot supply enough O2 to tissues.
Without enough O2, the body is NOT able to produce all of the ATP that is required.
The buildup of lactic acid can cause painful burning in your muscles!

28. Lactic acid fermentation—occurs in muscle cells
Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles
glucose lactic acid + carbon dioxide + 2 ATP

29. Comparing ATP Production
First, your body breaks down glucose through aerobic respiration to produce 36 ATP per glucose molecule; however, this is a slow process.
When muscle cells cannot get enough O2 they break down glucose through lactic acid fermentation to produce 2 ATP per glucose…
Therefore, AEROBIC RESPIRATION is much more efficient in terms of ATP production – ATP compared to 2 ATP!

30. Anaerobic Respiration: occurs when no oxygen is available to the cell (2 kinds: Alcoholic and Lactic Acid)
Also called fermentation
Much less ATP produced than in aerobic respiration

31. Alcoholic Fermentation
Anaerobic way of converting energy for yeast and other microorganisms
Glucose broken down to produce alcohol, CO2 and energy (ATP)
C6H12O6  ethanol + CO2 + 2 ATP
EX: baking bread with yeast
fermenting wine & beer

32. Alcoholic fermentation—occurs in bacteria and yeast
Process used in the baking and brewing industry—yeast produces CO2 gas during fermentation to make dough rise and give bread its holes
glucose ethyl alcohol + carbon dioxide + 2 ATP

33. 3rd Electron Transport Chain (ETC)
Summary:
3 steps:
1st glycolysis
2nd Krebs cycle
3rd Electron Transport Chain (ETC)

34. First step in anaerobic respiration is also glycolysis
Diagram
Anaerobic Respiration
Cytoplasm
Alcoholic fermentation
Bacteria, Yeast 2 ATP
C6H12O6
glucose
glycolysis
Lactic acid fermentation
Muscle cells ATP
ETC
Mitochondria
Krebs Cycle
Aerobic Respiration
36 ATP