1. Exercise Physiology APL2/L3

2. Our Body’s “gasoline”  Adenosine Triphosphate  Energy storing molecule  “usable energy”

3. Energy Pathways (3)  1.ATP (6 sec): stored in mitochondria.  2. CP: Creatine phosphate (10 sec) A lot of it in muscles and builds ATP back up. (Creatine phosphate + ADP ↔ ATP + creatine) (Creatine phosphate + ADP ↔ ATP + creatine)  3. Glycogen: stored glucose in liver and muscles.(anaerobic)  Fat: used last. Greatest potential energy source.

4. Cellular Respiration:  Process which releases energy from organic compounds in cells.  3 reactions: glycolysis, citric acid cycle (Krebs), electron transport chain  RESULT: CO2, H2O and energy. ½ IS HEAT, ½ IS USED TO MAKE ATP (ENERGY NEEDED BY MUSCLE CELLS)

5. Glycolysis:  Breaking of glucose: 6-carbon glucose molecule →two 3-carbon pyruvic acid molecules.  High energy electrons are delivered to ETC  2 molecules ATP produced

6. Krebs cycle  Part II of Aerobic Respiration  Charged Ions are produced and gotten ready for ETC.  2 ATP produced

7. Electron Transport Chain

8. ATP  Between ETC and Krebs Cycle: 34 molecules of ATP are produced.  A lot of heat is given off

10. Muscle fatigue and Oxygen Debt  Normally, we breath enough O2 to support aerobic use of glucose. However…  Strenuous use of muscles result in: anaerobic respiration: glucose is broken into pyruvic acid → lactic acid  Lactic acid: not enough ATP to convert it to glucose at this time.  Results in: O2 debt= muscle cramping/fatigue

11. Hypertrophy of Muscles  Muscles forcefully exercised will enlarge  There is ↑ in muscle fiber size, not number of muscles.  i.e: body builder/weight -lifter, prof. athlete

12. Atrophy of Muscles Atrophy of Muscles  Muscles not used will decrease in size  This is called muscle atrophy  i.e: spinal cord patients: very thin and frail

13. Quick Quiz (2 pts/bullet)  What is gasoline for our body?  What are the 3 energy pathways in the cell?  What 3 reactions make up cellular respiration and what do they produce?  When does anaerobic respiration occur?  How do muscles enlarge? What is increased muscle mass called?