1. “The Perfect Machine?”

2. “The Perfect Machine”?

3. “The Perfect Machine?”

4. “The Perfect Machine?”

5. Why Does The Metabolism Of All Living Organisms Prevent Them From Being “Perfect Machines”

6. Autotrophic Energy Flow
Autotrophs (producers) get their energy from the sun.
Producers convert this light energy into stored chemical energy (glucose).
This process is called photosynthesis.

7. Heterotrophic Energy Flow
Heterotrophs (consumers) get their energy from the Autotrophs (producers).
Heterotrophs convert the stored chemical energy of glucose into usable chemical energy (ATP).
This process is called cellular respiration.

8. Comparative Equations
Photosynthesis:
6 H2O + 6 CO2 + energy (sun) → C6H12O6 + 6 O2
Aerobic Cellular Respiration:
C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy (ATP)

10. Different Types of Cellular Respiration
Cellular respiration is a CATABOLIC reaction, meaning materials are broken down to provide energy for other substances to be “built up” (ATP)
Cellular Respiration may follow two distinct pathways
Anaerobic (oxygen absent)
Lactic Acid Fermentation
Alcoholic Fermentation
Aerobic (oxygen present)

11. Cellular Respiration and Inefficiency
686 kcal/mol of energy stored in glucose
ATP yields about 1.6 kcal/mol
Aerobic Respiration recharges 36 net ATP (40.6% efficient)
Lactic acid fermentation or alcoholic fermentation yield 2 net ATP, or about 4 kJ (2.5% efficient)

12. Where Is The Rest of The Potential Energy From Glucose?

13. Ethanol & Lactic Acid

14. Pathway 1a: Lactic Acid Fermentation
Where: Cytoplasm
What: Glucose is split into 3 carbon pyruvate, then into two, 3 carbon molecules of Lactic Acid.
Why: To recharge 2 ADP  2 ATP

15. Pathway 1b: Alcoholic Fermentation
Where: Cytoplasm
What: Glucose is split into pyruvate, then into 2 carbon molecules of ethanol and carbon dioxide
Why: To recharge 2 ADP  2 ATP

16. How Does Aerobic Respiration Differ From Anaerobic Respiration?

17. Aerobic Respiration C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP food
(glucose, a carbohydrate)
oxygen
water
carbon
dioxide

19. Glycolysis Krebs Cycle Electron Transport Chain
Aerobic Respiration
Glycolysis
Krebs Cycle
Electron Transport Chain

20. First Step of Aerobic Respiration: Glycolysis
Where: Cytoplasm
What: Glucose is split into two 3 carbon molecules called PYRUVATE
Why: To recharge 2 ADP  2 ATP

21. Mitochondria Form & Function
Plant and animal cells contain mitochondria: cell structures that transfer some of the chemical energy in glucose to ATP.
In the mitochondria, a cytoplasm-like MATRIX is surrounded by a folded membrane with high surface area called the CRISTAE

22. Second Step of Aerobic Respiration: The Krebs Cycle
Where: Intracellular matrix of mitochondria
What: Products of glycolysis broken down in a series of cyclical chemical reactions. CO2 is released as waste
Why: To recharge 2 ADP  2 ATP

23. Third Step of Aerobic Respiration: The Electron Transport Chain
Where: Cristae of mitochondria
What: Electrons produced from breakdown in Krebs Cycle used to power synthesis of ATP
Why: To recharge 34 ADP  34 ATP

24. Why is aerobic respiration so much more efficient?

25. Aerobic Respiration & ATP
The waste byproducts of aerobic respiration are simpler (CO2)
Therefore, more energy is available to recharge ATP from ADP and Phosphate
As a result of this higher efficiency, aerobic organisms can be more complex, active and have longer-life spans.