Student%20Lecture%203%20%28Bioenergetics%29

Student%20Lecture%203%20%28Bioenergetics%29 - Lecture 3...

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Unformatted text preview: Lecture 3 Bioenergetics Bioenergetics Tuesday 1­19­09 Outline Outline Quiz Bioenergetics Mitochondrial Biogenesis Extra Credit – – – – – Friday, January 29 Dr. Jesse Witt Assistant Professor Psychological Sciences Performance affects perception: Evidence form size, shape, and speed judgments – LAMB 108, 1:30 P.M. Adenosine Triphosphate (ATP) Adenosine Primary energy carrying molecule in the cell. Store ______ μmol ATP/g muscle Exercise utilizes ____μmol ATP/g muscle/second Stored ATP can supply energy for ___ second of exercise Structure – – – Adenine Ribosome ____________________ Reaction ATP ADP + Pi + Energy _______ Figure 3.10 What happens after ATP is depleted What happens after ATP is depleted and ADP concentrations are increased? ATP-PC System ATP-PC “Phosphagen System” Increased concentrations of ____ stimulate – ________________ – ________________ – ________________ PC (phosphocreatine) + ADP ↔ ATP + creatine ADP + ADP ↔ ATP + AMP AMP → IMP (inosine monophosphate) + NH3 (ammonia) Duration of exercise using ATP­PC system is less than ___sec. Is there a method of increasing the Is there a method of increasing the concentration of phosphocreatine (PC) within skeletal muscle cells? Creatine monohydrate Supplementation Supplementation ___g/day over 5 days increases intramuscular stores of PC Improves performance in __________________________________ ________________________ Improves strength and decreases fat free mass when used in conjunction with ______________. Results on running and swimming performance are _____________. Glycolysis Glycolysis Pathway used to transfer bond energy from glucose to rejoin Pi and ADP. Takes place in the __________. Broken up into two phases – ______________ During this phase phosphates are added to glucose and fructose 6 phosphate by ATP During this phase ATP and NADH are generated – _______________ What is the net ATP production What is the net ATP production from one glucose molecule under anaerobic conditions? One molecule of glucose produces __ molecules of ATP. However, ___ molecules of ATP are initially utilized. Therefore, the net ATP production from ___ molecule of glucose under anaerobic conditions is ___ ATP. Fig 3.16 Fig 3.15 What is the net ATP production What is the net ATP production from one glycogen molecule under anaerobic conditions? One molecule of glycogen produces __ molecules of ATP. However, __ molecules of ATP is initially utilized. Therefore, the net ATP production from __ molecule of glucose under anaerobic conditions is ___ ATP. Fig 3.15 Fig 3.14 What is the net ATP production What is the net ATP production from one triglyceride or protein molecule under anaerobic conditions? Under anaerobic conditions _________________________ can combine ADP and Pi to produce ATP Fig 3.19 How does the presence of oxygen How does the presence of oxygen effect glycolysis? Under aerobic conditions pyruvate is not converted to lactate is Under aerobic conditions pyruvate is not converted to lactate. Transported into the __________ ______ to electron transport chain Fig 3.15 Krebs Cycle Krebs Aerobic production of ATP _____________ Produced ___ ATP per cycle (2 ATP per molecule of glucose) Utilizes _______ carriers – Nicotinamide adenine dinucleotide (NAD) – Flavin adenine dinucleotide (FAD) Krebs Cycle (cont) Krebs Fig 3.18 What happens to the hydrogen carriers What happens to the hydrogen carriers (NADH & FADH) Electron Transport Chain Electron Inner mitochondrial membrane Electronsare released from NADH and FADH and move down ___________. The movement of electrons down cytochromes forces _____ across membrane. H+ movement causes ADP+Pi → ATP NADH = ____ ATP FADH = ____1.5 ATP 02 combines with H+ to produce H2O at end of ETC. Fig 3.20 Putting it all together Putting 1 ATP _ NADH 1 FADH __ NADH = 25 ATP 2 FADH = 3 ATP __ ATP 2 NADH 1 ATP _ NADH 1 FADH Total ATP from 1 molecule of glucose = 32 Glycogen = ?? Enzymes that regulate bioenergetics bioenergetics ATP­PC – ________ Glycolysis – _________________ Krebs Cycle – ________________ ETC – ____________________ – Stimulators – ADP – Inhibitors ­ ATP Interaction between aerobic and anaerobic pathways during exercise anaerobic Fig 3.24 Bioenergetic: physiological adaptations to exercise adaptations *Mitochondria *Mitochondria Majority of ATP production Two types Intermyofibrillar mitochondria Subsarcolemmal mitochondria – __________________ ______________ – __________________ ______________ Subsarcolemmal mitochondria Intermyofibrillar mitochondria ACSM Advanced Exercise Physiology Exercise and Mitochondria Exercise 4­6 weeks of endurance training can increase mitochondrial content __________%. Factors – Intensity and duration of exercise – ______________ (mitochondrial density) Type IIB fiber types have greater potential for increasing mitochondrial content. – Exercise produces a greater increase in _____________ compared to _______________________mitochondria. *Experimental methods of measuring mitochondrial content measuring Organelle volume to cellular volume Untrained Mitochondria is 4.9% of total volume. Leek, B.T et al. AJP 2001 Sedentary Chronic Exercise Training Experimental methods of measuring mitochondrial content (cont.) mitochondrial ______________________ Procedures – Collect muscle sample – Liberate mitochondria – Chemical reaction Homogenizing, Vortexing, Sonicating, Freezing (x3) acetyl­CoA + oxaloacetate + H2O → citrate + CoA­SH + H+ (side reaction: CoA­SH + DTNB → mercaptide ion) – Measure mecaptide ion absorbance rates using a spectrophotometer – Higher rates of absorbance means increased citrate synthase activity and mitochondrial content. *Increased mitochondrial content = increased potential for ___ production increased ACSM Advanced Exercise Physiology Signals for increasing mitochondrial content within muscle content ____________ ­knockout animals with ↓ ATP and ↑AMP have ↑mitochondrial content. ____________ ­Drug A23187 ↑ intracellular Ca++ and increased mitochondrial enzymatic activity Molecular pathway for mitochondrial biogenesis mitochondrial Ca++ & ATP turnover stimulate protein kinases and phosphatases in cytosol (AMPK, CaMK, p38) Once activated AMPK, CaMK and p38 translocate to nucleus and phosphorylate transcription factors in nucleus. This increases transcription and mRNA production. mRNA stability within the cytosol is increased during exercise. (RNase resistant) Synthesis of nuclear­encoded mitochondrial proteins (NEMP) occur in cytosol ACSM Advanced Exercise Physiology Mitochondria also has DNA in which 13 critical proteins for mitochodria are encoded NEMPs are made with positively charged N­terminal which chaperone proteins bind and guide NEMPs to mitochondria NEMP unfolds and moves through the outer membrane translocase complex (TOMs) and inner membrane translocase complex (TIMs). (note exercise increases the protein import machinery) Inside mitochondria N terminal is cleaved by mitochondrial processing peptide (MPP) and NEMP becomes a mature mitochondrial protein. N terminal activates mitochondrial transcription factor A (Tfam) which initiates mitochondrial transcription and protein synthesis. Protein derived from translation of nuclear and mitochondrial mRNA combine and begin enlarging the mitochondria. Molecular pathway for mitochondrial biogenesis mitochondrial ACSM Advanced Exercise Physiology Rest is crucial for mitochondrial biogenesis biogenesis Mitochondrial biogenesis requires ______ At rest ATP can be utilized for processes such as __________ and _______________. ...
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This note was uploaded on 02/17/2011 for the course HK 458 taught by Professor Newcomer during the Spring '10 term at Purdue University-West Lafayette.

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