IB Sport Science 3.3 Study Guide PDF

IB Sport Science – 3.3 Expanded Study Guide Energy Systems and ATP Production The body utilizes three primary energy systems to regenerate ATP, depending on the intensity and duration of exercise. Understanding these systems and their metabolic pathways is essential for optimizing athletic perform...

IB Sport Science – 3.3 Expanded Study Guide Energy Systems and ATP Production The body utilizes three primary energy systems to regenerate ATP, depending on the intensity and duration of exercise. Understanding these systems and their metabolic pathways is essential for optimizing athletic performance and recovery. ATP Yield and Metabolic Pathways ​ The Electron Transport Chain (ETC) produces the greatest ATP yield, generating 34-36 ATP per glucose molecule in the aerobic energy system. ​ Glycolysis is a common pathway in both anaerobic and aerobic metabolism, breaking down glucose into pyruvate. ​ In aerobic conditions, pyruvate enters the Krebs cycle and is further processed through the ETC, yielding 38 ATP per glucose. ​ In anaerobic conditions, pyruvate is converted into lactic acid, producing only 2 ATP per glucose molecule. ATP Resynthesis During Exercise  ​ The ATP-PC system provides immediate ATP through the breakdown of creatine phosphate (PCr), making it the fastest ATP resynthesis system, but it is depleted within 10 seconds. ​ The Lactic Acid System (anaerobic glycolysis) fuels activities lasting 10-90 seconds, producing 2 ATP per glucose with lactic acid as a byproduct. ​ The Aerobic System produces ATP over extended periods through oxidative metabolism, using glucose, glycogen, and fats as fuel sources. Cellular Respiration and ATP Breakdown ​ Cellular respiration is the controlled release of energy from organic compounds to synthesize ATP. ​ ATP breakdown releases energy when a phosphate group is removed, converting ATP to ADP (adenosine diphosphate). This reaction is catalyzed by the enzyme ATPase. ​ ATP is resynthesized when ADP gains a phosphate group, facilitated by ATP Synthase. ​ The mitochondria play a crucial role in ATP production, particularly in the aerobic system. Energy System Contributions to Sport and Exercise Each energy system predominates in different types of physical activity: ​ ATP-PC System: Used for explosive, short-duration movements such as sprinting (100m), weightlifting, and shot put. ​ Lactic Acid System: Used for high-intensity efforts lasting 10-90 seconds, including 400m sprints, HIIT workouts, and wrestling. ​ Aerobic System: Predominant in long-duration, endurance activities such as marathons, cycling, and soccer. Energy System and Byproducts ​ ATP-PC System: Byproduct is creatine and inorganic phosphate but does not produce fatigue-inducing substances. ​ Lactic Acid System: Byproduct is lactic acid and hydrogen ions (H+), leading to muscle fatigue. ​ Aerobic System: Byproducts are water (H2O) and carbon dioxide (CO2), which do not contribute to fatigue. Physiological Adaptations in Athletes ​ Highly trained athletes develop adaptations that reduce oxygen deficit at the start of exercise. ​ They also demonstrate greater lactic acid clearance, leading to improved endurance and faster recovery. Training Considerations for Energy Systems ​ ATP-PC System Training: Short, maximum-effort bursts (5-10 sec) with full recovery (2-3 min). ​ Lactic Acid System Training: Repeated high-intensity efforts of 15-60 sec with short recovery (30-90 sec). ​ Aerobic System Training: Long-duration, moderate-intensity exercise to improve mitochondrial efficiency. Graph Interpretation and Sport-Specific Applications ​ Aerobic System: Dominates endurance activities, showing gradual ATP production. ​ ATP Store: Represents limited immediate energy available for use. ​ ATP-PC System: Displays a rapid peak in ATP production but quick depletion. ​ Lactic Acid System: Shows moderate ATP production with a steady decline as lactic acid accumulates. Identifying Sports for Each Energy System ​ ATP-PCr System: Sprinting, weightlifting, jumping events. ​ Lactic Acid System: 400m sprints, wrestling, rowing (mid-distance). ​ Aerobic Respiration System: Long-distance running, cycling, swimming. Discuss the characteristics of each energy system and their role in exercise: ATP-PC System ​ Fuel Source: Creatine phosphate (PCr) ​ Intensity: High-intensity, explosive efforts ​ Duration: 0-10 sec ​ Example Activity: 100m sprint, Olympic lifts ​ ATP Production: 1 ATP per PCr molecule ​ Byproducts: Creatine and inorganic phosphate Lactic Acid System ​ Fuel Source: Glycogen/glucose ​ Intensity: Moderate to high-intensity efforts ​ Duration: 10-90 sec ​ Example Activity: 400m sprint, wrestling, HIIT workouts ​ ATP Production: 2 ATP per glucose molecule ​ Byproducts: Lactic acid and hydrogen ions Aerobic Respiration System ​ Fuel Source: Glucose, glycogen, and fats ​ Intensity: Low to moderate intensity ​ Duration: Long-duration activities (90 sec+) ​ Example Activity: Marathon running, cycling ​ ATP Production: 38 ATP per glucose molecule ​ Byproducts: Water (H2O) and carbon dioxide (CO2)