1. Energy Transfer

2. ATP
“Energy Currency”
Potential energy in ATP used for all energy requiring processes of cells

3. Energy Transformation
Formation of ATP from food
Use of chemical energy in ATP for metabolic work

4. ATP Hydrolysis ATP + H2O ADP + Pi – 7.3 kcal/mol
ATPase
Anaerobic Process – generates energy for immediate use
Energy Liberating

5. Energy Currency CHO, Lipids, and Proteins + O2 CO2 + H2O ADP + Pi ATP
Synthesized End Products
Precursors

6. ATP stored only in cells total quantity  3.5 oz.
energy for few seconds

7. ATP Generation
ATP-CP system
glycolytic system
oxidative system

8. Creatine Phosphate ATP  ADP + P + Energy CP  C + P + Energy
Biological Work
ATPase CK

9. Creatine Phosphate 4 - 6x conc. of ATP
Energy released when C & P bond broken
Energy used to phosphorylate ADP
Used in activities < sec.
Anaerobic

10. Cellular Oxidation – Aerobic Metabolism
Cellular oxidation-reduction is the mechanism for energy metabolism
Electron Transport
Oxidative Phosphorylation

11. Electron Transport Oxidation of hydrogen
Exergonic transport of electrons to oxygen
electrons  oxygen  H2O
ADP is phophorylated (energized)

12. Electron Transport (Respiratory Chain)
ATP
NADH + H+
FADH2
ATP
2e-
NAD+
Coenzyme Q
2e-
FAD
2e-
Coenzyme b
2e-
ATP
Coenzyme c
Coenzyme c1
2e-
Coenzyme aa3
½ O2
2e-
2H+
H2O

13. Oxidative Phosphorylation
10 means for extracting & trapping energy (PO4)
>90% of ATP synthesis takes place in respiratory chain via oxidative reactions w/ phosphorylation

14. Oxidative Phosphorylation
ATP is synthesized when electrons transferred from NADH to O2
NADH + H+ + 3ADP +3P + ½ O2 
NAD+ +H2O + 3ATP

15. Electron Transport-Oxidative Phosphorylation Efficiency
Oxidation of 1 mole of NADH  52 kcal
3 moles of ATP regenerated (3 moles * 7 kcal/mole = 21 kcal)
21/52 = 40% efficient
60% dissipates - body heat

16. Role of Energy Release from Food
Phosphorylate ADP  ATP

17. Regeneration of ATP Liver - amino acid - glycogen  glucose
Adipocytes  fatty acids
Mitochondrion
Muscle
- ATP, CP, triglycerides, glycogen, AA

18. Energy Release - CHO Only macronutrient to generate ATP anaerobically
Light-moderate exercise provides ½ of energy
C6H12O6 + 6O2  6 CO2 + 6 H2O – 689 kcal/mol

19. Glycolysis - anaerobic
- glucose  pyruvate (2)
Pyruvate  lactic acid (2)
net gain 2 ATP  5% of total ATP generated in glucose breakdown (rapid)

20. Lactic Acid If energy demands exceed O2 supply or
rate of H+ production exceeds usage
High intensity exercise  LA in muscle  blood (buffered)  lactate  energy metabolism
used during moderate exercise

21. Aerobic Metabolism Kreb’s Cycle (2 ATP) Electron Transport (2 ATP)
Oxidative Phosphorylation (32 ATP)

22. Lipid Catabolism Greatest source of potential energy
90, ,000 kcal

23. Sources Triglycerides stored in muscle
Triglycerides in lipoprotein complexes
FFA (triglyceride + 3 H2O  glycerol + 3 FA)

24. Utilization FA diffuse from adipocytes  FFA
controlled by epi, norepi, glucagon, GH
Meal  triglyceride synthesis
Moderate exercise   FA utilization  triglyceride breakdown

25. Energy Transfer - Lipid
18 carbon FA  146 ATP (438 ATP total) + 19 ATP (glycerol)
40% efficiency
30-80% of energy for biological work is provided by lipids

26. Energy Release - Protein
20 sustained exercise / intense training
AA (deaminated)  carbon skeleton  Kreb’s cycle
AA (deaminated )  pyruvate (gluconeogenesis)

27. Interrelationships Kreb’s Cycle
- link between food energy & chemical energy
- provides intermediate substances  mitochondria  bionutrients for growth & maintenance

28. Interrelationships Lipids more efficiently used in presence of CHO
lipid catabolism is dependent on oxaloacetate (Kreb’s - generated from pyruvate in CHO catabolism)

29. Interrelationships
Power output by lipids alone is only 1/2 that of when CHO is primary source
serve CHO depletion  acetyl-CoA & FFA  ketone bodies (ketosis)
Liver