Bioenergetics PDF

KIN 476 Module 1: Bioenergetics Chapter 2 0 1 What is metabolism? Besides a lot of big random sounding enzymes “The total sum of all chemical reactions that occur in the body” —Metabolism Two main types of metabolism Anabolic – “Anaboli...

KIN 476 Module 1: Bioenergetics Chapter 2 0 1 What is metabolism? Besides a lot of big random sounding enzymes “The total sum of all chemical reactions that occur in the body” —Metabolism Two main types of metabolism Anabolic – “Anabolism” Synthesis or “building” of molecules Catabolic – “Catabolism” Breakdown of molecules “The process of converting food (fats, CHO, protein) into a usable form of energy” —Bioenergetics ATP Adenosine Triphosphate Adenosine Triphosphate Three phosphate  Resting [ATP] should not be thought of as an energy store (~90 g total) Resting intramuscular concentration = 5mmol/kg  Resting [ATP] should not be thought of as an energy store (~90 g total) Resting intramuscular concentration = 5mmol/kg  Resting [ATP] should not be thought of as an energy store (~90 g total) Resting intramuscular concentration = 5mmol/kg Muscle contraction can increase cellular demand for ATP by 500-1,000 times! Macronutrients Protein s 4 kcals Macronutrients Protein s 4 kcals Carbs 4 kcals Macronutrients Protein s 4 kcals Carbs 4 kcals Fats 9 kcals Macronutrients Protein s 4 kcals Carbs 4 kcals Fats 9 kcals Macronutrients and Exercise  Quiz!!! What is the resting intramuscular concentration of ATP? What is the definition of bioenergetics? What is the most calorie dense macronutrient?  ATP Production 02 The journey of 1000 ATPs starts with a single glucose  Enzymes Protein Molecules Do not cause reactions Speed up reactions Lower the activation Can go energy either way! Enzymes Factors: pH Optimal pH Enzyme Activity p Enzymes Factors: pH Enzymes Factors: pH example Enzymes Factors: Temperature Enzymes Factors: Temperature Enzymes Factors: Temperature The Big 3 The big three Phosphagen 1st and shortest Glycolysis 2nd with two types Oxidative Phosphorylation 3rd and long duration exercise Other class’s energy system We will not be using this timing  Phosphagen ~3-15 Seconds Know this Anerobic Glycolysis by heart! ~15-120 Seconds Oxidative Phosphorylation > 120 Seconds  Phosphagen ~3-15 Seconds Anerobic Glycolysis ~15-120 Seconds Oxidative Phosphorylation > 120 Seconds Energy Systems Requires No O2 O2 Goal: Regenerate ATP  Characterized by Duration of ATP production/synthesis Rate of ATP production/synthesis Aerobic or anaerobic conditions Where they occur in the body Why we need these systems Sprinting can cost ~3.7 mmol/kg/s of ATP How long would the average person be able to sprint on just resting concentrations of ~1.4ATP? seconds Why we need these systems Moderate cycling can cost ~0.4 mmol/kg/s of ATP How long would the average person be able to cycle on just resting concentrations of ATP? 12.5 seconds  03 Anaerobic We don’t need no oxygen Two main Anaerobic Systems Phosphagen Duration: ~3-15 seconds Anaerobic Glycolysis Duration: ~15 seconds -2 minutes Phosphagen Energy System Adenosine PO4-3 PO4-3 PO4-3 Creatine PO4-3 Phosphagen Energy System Adenosine PO4-3 PO4-3 Creatine PO4-3 Phosphagen Energy System Adenosine PO4-3 PO4-3 Creatine Kinase Creatine PO4-3 Phosphagen Energy System Adenosine PO4-3 PO4-3 Creatine Kinase Creatine PO4-3 Phosphagen Energy System Adenosine PO4-3 PO4-3 PO4-3 Creatine Kinase Creatine Phosphagen Energy System Adenosine PO4-3 PO4-3 PO4-3 Creatine Kinase Creatine Phosphagen Energy System Phosphagen Energy System Phosphagen Energy System Phosphagen Energy System Creatine PO4-3 Creatine PO4-3 Adenosine PO4-3 PO4-3 Creatine PO4-3 Creatine PO4-3 Creatine PO4-3 Creatine PO4-3 ADP + PCR  ATP + Cr Creatine kinase (CK)  CK controls rate of ATP production Negative Feedback system When ATP levels  (ADP ), CK activity  ADP + PCR  ATP + Cr When ATP levels  CK activity   CK controls rate of ATP production Negative Feedback system When ATP levels  (ADP ), CK activity  When ATP levels  CK activity  Creatine Supplementation Increases intramuscula r PCR stores so they don’t run out at quickly Creatine Supplementation Increases intramuscula r PCR stores so they don’t run out at quickly CHO Metabolism Anaerobic CHO Metabolism Aerobic Glycolysis Primary Functions Degrade glucose and glycogen into pyruvate Regenerate ATP Produce NADH Nicotinamide adenine dinucleotide TWO PHASES Energy Investment Energy Payoff Step 1-5 Step 6- 10 Hexokinase Phosphoglucose Isomerase Rate Limiting Step Aldolase triose phosphate isomerase  Review Quiz! 1.What does the term allosteric mean? 2.What is the major allosteric enzyme of glycolysis? 3.What step does it work? 4.How many steps is the energy investment phase?  G3P Dehydrogenase ONLY REDOX REACTION! Phosphoglycerate Kinase Phosphoglyceromutase Enolase Pyruvate Kinase  Review Quiz! 1.What steps are the one way reactions in glycolysis? 2.What step is different if starting with glycogen? 3.What step is the only redox reaction?  Hexokinase Step 1 Allosteric PFK (Rate Step 3 limiting) Pyruvate Kinase Enzymes Step 10 Glycolysis Net Yield from Glucose 2 ATP (2 Invested, 4 Produced) 2 Pyruvate 2 NADH 2 H2O Glycolysis Net Yield from Glycogen 3 ATP (1 Invested, 4 Produced) 2 Pyruvate 2 NADH 2 H2O You need to know these 3 Anaerobic Glycolysis (Furmentation)  Lactate vs Lactic Acid Not really in the human body In the human body Sarcoplasm Adenosine PO4-3 PO4-3 PO4-3 Adenosine PO4-3 PO4-3 PO4-3 NADH Blood Sarcoplasm Adenosine PO4-3 PO4-3 H+ Adenosine PO4-3 PO4-3 PO4-3 NADH pH ↓ Blood Sarcoplasm Adenosine PO4-3 PO4-3 H+ Adenosine PO4-3 PO4-3 H+ NADH pH ↓ ↓ Blood Sarcoplasm Adenosine PO4-3 PO4-3 H+ Adenosine PO4-3 PO4-3 H+ NAD+ H+ pH ↓ ↓ ↓ Blood Sarcoplasm Adenosine PO4-3 PO4-3 H+ Pyruvate Adenosine PO4-3 PO4-3 Pyruvate H+ Pyruvate NAD+ H + pH ↓ ↓ ↓ Blood Sarcoplasm Adenosine PO4-3 PO4-3 H+Pyruvate Lactate Adenosine PO4-3 PO4-3 H+Pyruvate Lactate H+Pyruvate Lactate NAD pH ↓ ↓ ↓ + Blood Sarcoplasm Adenosine PO4-3 PO4-3 Lactate Adenosine PO4-3 PO4-3 Lactate NAD+ pH ↓ ↓ Lactate Blood Sarcoplasm Adenosine PO4-3 PO4-3 Lactate Adenosine PO4-3 PO4-3 NAD+ pH ↓ Lactate Lactate Blood Sarcoplasm Adenosine PO4-3 PO4-3 Adenosine PO4-3 PO4-3 NAD+ pH Lactate Lactate Lactate Blood Sarcoplasm Adenosine PO4-3 PO4-3 Adenosine PO4-3 PO4-3 ← to step 6 of glycolysis pH Lactate Lactate Lactate Blood Sarcoplasm Adenosine PO4-3 PO4-3 Adenosine PO4-3 PO4-3 pH To the liver to be converted to glucose → using the Cori cycle Blood Sarcoplasm ↑ To step 7 or 10 of glycolysis pH Blood Does lactic acid cause the burn? THE BURN IS CAUSED BY DECREASING MUSCLE PH DUE TO HYDROGEN PRODUCTION FROM MUSCLE CONTRACTION. LACTATE HELPS BUFFER HYDROGEN BUILD UP DURING INTENSE EXERCISE TO TRY AND PREVENT Can be used as a measure of intensity and effort! Lactate Threshold Lactate threshold (LT): point at which blood lactate accumulation increases markedly Indicator for the amount of anaerobic metabolism occurring Lactate levels At rest: < 2 mmol/L Maximal Exercise: Can exceed 10 mmol/L Lactate Threshold Expressed as % of VO2max Untrained: 40- 60% Trained: 70-80% Lactate Threshold Testing Energy Oxygen Overall Relative ATP formed Available system necessary? chemical rate of ATP per capacity reaction formed per molecule of second substrate ATP-PCr No PCr to Cr 10 1 65% VO2max)  CHO are primary fuel “Crossover” concept shift from fat to CHO as exercise intensity increases We measure using RQ Respiratory Quotient Reading RQ Scale of 0.7-1.0 0.7 = 100% Fat utilization 1.0 = 100% CHO  At 3:29 VO2 was 1542 ml of O2 At 3:29 VCO2 was 1344 ml of CO2 RQ = VCO2 / VO2 RQ = 1344/1542  Kcal/min = 1.542 LO2/min x 4.887 Kcal/LO2 7.5 kcals/min If they exercised at this intensity for 30 min? 30 min x 7.5 kcals/min = 225 kcals