1. Bioenergetics

2. Definition: Converting food into energy

3. Nutrients from Food: (Macromolecules) Carbohydrates Lipids Proteins Used to acquire, use, and store energy.

4. 1. Carbohydrates in the Body Found as: 1.Glucose (from food)  Found as blood sugar 2.Glycogen  Storage form of glucose (storage molecules are bigger….polysaccharide)  Found in liver and muscle

5. 2. Fats in the Body 1.Fatty acids - fuel 2.Triglycerides  Storage form of fat in muscle and adipose tissue  There are 9kCal in one gram of fat Twice the amount of carbs or proteins

6. 3. Proteins Not a primary fuel source during exercise Used to build muscle

7. Question… What is the energy molecule used by the cell?

8. ATP = MVP

9. Mitochondria “Powerhouse of the cell” Site of ATP production

10. ATP Adenine Ribose 3 Phosphates Energy is held within the bonds between the phosphates (Pi)

11. ATP is required for muscles to do work

12. ATP Source of energy for all cellular activities ATP allows for muscle contractions.

13. How to get more ATP? Muscle cells can produce ATP 2 ways: 1.Anaerobic pathways  Phosphocreatine breakdown  Glycolysis 2.Aerobic pathways  Aerobic Respiration  (Oxidative phosphorylation)

14. 1. Phosphocreatine Breakdown Anaerobic Creatine + Phosphate = Phosphocreatine Immediate source of 2ATP Can get the ATP in as little as 7 seconds

15. ATP-PC System and Exercise Used for short bursts of muscle power Ex.  A sprint  Gymnastics vault  High jump  Football play  All require a few seconds to complete and need a fast supply of energy

16. Phosphocreatine Breakdown

17. 2. Glycolysis Anaerobic Glycogen (polysaccaride)  Stored in the muscle and liver 1.Glycogen is converted to: glucose then… 2.converted to pyruvic acid which is converted to lactic acid 3.End result: 2 ATP

18. Glycolysis Used for short intense exercise  400m dash Glycogen stores in liver can last up to 2hrs  Football players tested post game showed 80% of glycogen stores were used

19. Glycolysis

20. Lactic Acid Accumulation of LA in muscle inhibits glycolysis  Therefore… no ATP production This leads to fatigue

21. Lactic Acid LA = no glycolysis = no ATP Muscle no longer performs effectively

22. Short-term, High Intensity Exercise More contributions from the anaerobic pathways  100m dash  Football  Basketball  Baseball

23. 3. Aerobic Pathway Oxidative Phophorylation  (Aerobic Respiration) All take place inside the mitochondria Produces the most ATP (36 molecules)  The slowest pathway

24. 3 Steps of Aerobic Pathway (FYI…) 1. Glycolysis Breakdown of glucose, fatty acids, and sometimes protein into Acetyl-Co A 2. Krebs Cycle Complete the breakdown of carbs, fats, and AA to create NADH FADH 3. Electron Transport Chain  Creates 32 ATP molecules

25. Aerobic Pathway

26. At Rest - Homeostasis Body’s energy requirement remains constant because the body is at rest 100% ATP comes from aerobic respiration

27. Aerobic Pathway and Exercise You can continue exercising…. As long as nutrients last:  Glucose  Glycogen  Fatty Acids  Triglycerides There is no lactic acid build up  LA = fatigue

28. Pathway for ATP is influenced by: 1.Exercise duration 2.Intensity Short term bursts of activity  Generally use anaerobic pathways Long term activity  Marathon  Cross Country running  Cross country skiing  ATP produced aerobically

29. Both Pathways: Events longer than 20 sec, but less than 10 minutes  Use a combination of aerobic and anaerobic  Gradual shift from one pathway to another

30. Interaction Between Aerobic/Anaerobic ATP Production Figure 3.23 Contribution of Aerobic/Anaerobic ATP Production During Sporting Events

31. Moderate Intensity / Long Term Exercise: Aerobic Pathway for ATP

32. What influences ATP Production? High levels of ATP inhibit ATP production  If you have it, you don’t need it High levels of ADP+P i stimulate ATP production Control of Bioenergetics

33. Training & ATP Training can increase skeletal muscle to use fats  This saves glycogen and improves performance.  Limits the amount of Lactic Acid produced. Increases enzyme size and activity Mitochondria gets larger  More area for RXN  More enzymes

34. Conclusions: Short-term, high-intensity activities  Greater contribution of anaerobic energy systems Long-term, low to moderate-intensity exercise  Majority of ATP produced from aerobic sources Most sports utilize a combination of aerobic and anaerobic metabolic pathways.

36. In Summary  During high-intensity, short-term exercise (i.e., two to twenty seconds), the muscle’s ATP production is dominated by the ATP-PC system.  Intense exercise lasting more than twenty seconds relies more on anaerobic glycolysis to produce much of the needed ATP.  Finally, high-intensity events lasting longer than forty-five seconds use a combination of the ATP- PC system, glycolysis, and the aerobic system to produce the needed ATP for muscular contraction. Metabolic Responses to Exercise: Influence of Duration and Intensity

37. Synthesis Breakdown ADP + P i  ATP ADP + P i + EnergyATP ATPase High-Energy Phosphates ATP

38.  Energy to perform exercise comes from an interaction of anaerobic and aerobic pathways.  In general, the shorter the activity (high intensity), the greater the contribution of anaerobic energy production. In contrast, long-term activities (low to moderate intensity) utilize ATP produced from aerobic sources. In Summary Interaction Between Aerobic/Anaerobic ATP Production

39. Enzymes Catalysts that regulate the speed of reactions  Lower the activation energy Are very specific  Lock and key model What if there was no ATP-ase? Biological Energy Transformation

40. Enzymes Biological Energy Transformation Figure 3.6 Enzymes lower the activation energy Reaction happens faster

41. Factors That Alter Enzyme Activity Temperature  Small rise in body temperature increases enzyme activity  Very high temp (fever) denatures enzymes pH  Changes in pH reduces enzyme activity  Lactic acid produced during exercise Biological Energy Transformation

42. Quiz: 1.The most valuable player of energy is 2.glycolysis requires o2 for atp production t/f 3.A marathon runner will produce most of the atp they need during _____________ pathways 4.Aerobic atp production takes place in the ______________.

43. Biological Energy Transformation Cellular Chemical Reactions Endergonic reactions  Require energy to be added  Endothermic Exergonic reactions  Release energy  Exothermic

44. Cellular Chemical Reactions Coupled reactions  Release of energy in an exergonic reaction drives an endergonic reaction  Example: Oxidation / reduction reactions

45. Biological Energy Transformation Figure 3.4 The energy given off by the exergonic reaction powers the endergonic reaction Coupled Reactions

46. Oxidation-Reduction Reactions Oxidation  A reaction where an electron is removed Reduction  A reaction where an electron is added Oxidation and reduction are always coupled reactions Biological Energy Transformation

47. Does Creatine Supplementation Improve Exercise Performance? Depletion of PC may limit short-term, high- intensity exercise Creatine monohydrate supplementation  Increased muscle PC stores  Some studies show improved performance in short- term, high-intensity exercise Inconsistent results may be due to water retention and weight gain  Increased strength and fat-free mass with resistance training Creatine supplementation does not appear to pose health risks Bioenergetics