KIN 100 1st Edition Lecture 4Metabolism● Sources of energy○ Immediate energy source- in the muscles○ Short term- glucose○ long term- fat storesAnaerobic metabolism● energy creation without O2○ Immediate- in muscle fibers● ATP - adenosine triphosphate● CP- creatine phosphate■ Using ATP● Third phosphate is released from molecule and releases energy○ ATP-> ADP+ P+ heat+ energy■ Using CP● CP + ADP -> ATP + Creatine○ creatine kinase (CK)- enzyme that helps with reaction○ reaction takes ADP from ATP reaction above.○ Short term■ glycolysis● goal- make ATP from glucose● most glucose is stored as glycogen○ glycogenolysis- conversion of glycogen to glucose● glucose is broken into 2 pyruvate molecules and ATP○ pyruvate can be converted to ATP○ pyruvate can be converted to lactate, which can be converted to ATP● Lactate○ lactate + hydrogen ion (H+) =lactic acid■ lactic acid- impairs muscle contraction■ acidosis- muscles become too acidic ○ good energy source○ Lactic acid shuffle■ slow-twitch fibers use energy from lactic acid made by fast-twitch fibers● glucose paradox○ glycogen supply is limiting○ liver has lots of glycogen, but prefers to make glucose from lactic acid■ why not use glucose?● no negative side effects○ glycolysis release only 5% of the total energy in glucoseOxidative Metabolism○ creates more ATP● Krebs Cycle○ Pyruvate -> acetyl CoA+ hydrogen■ hydrogen is oxidized for more energy■ occurs in mitochondria■ requires oxygen■ Acetyl CoA- Vitamin B derivative● Electron Transport Chain (ETC)○ uses by-products of Krebs Cycle○ occurs in mitochondria○ by products- H2O, CO2, Heat● Summary○ O2 + glucose-> ATP + CO2 + H2O + heat○ 1 glucose molecule= 38 ATP■ 4-Krebs■ 34- ETCFat Metabolism○ Adipose Tissue○ fat cells = adipocytes■ largely subcutaneous tissue■ composed of triglycerides● triglyceride= glycerol + 3 free fatty acids (FFA)● Beta-oxidation○ uses FFA■ FFA-> acetyl CoA->Krebs or ETC○ generation of oxygen carriers from FFA○ facilitated by epinephrine, caffeine ○ yields 460 ATPEnergy From Protein○ contains nitrogen○ deamination- removal of N2○ results in creation of metabolites-pyruvate■ pyruvate enters Krebs CycleNuclear Magnetic Resonance Spectroscopy (NMR)● non-invasive way to measure phosphorus, carbon, etcDistance 100m 400m 1500m 5000m marathonTime 10 s 45s 3:30 min 15 min >2 hours% Aerobic 1 15 50 80 99%Anaerobic 99 85 50 20
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