A mаrаthоn runner nоtices thаt her perfоrmance drops dramatically near the end of long races. Even though she trained extensively, she experiences severe fatigue and muscle weakness during the final stages of the event. Sports scientists explain that endurance performance depends heavily on the body’s ability to produce ATP efficiently through cellular respiration. As exercise continues and energy reserves change, the body must rely on metabolic pathways that convert stored nutrients into usable cellular energy. You have been asked to explain the biochemical processes that allow cells to generate energy during prolonged physical activity. Your Task Part I: Using concepts from this unit, explain the following: Why is ATP considered the main energy currency of the cell? How does the citric acid cycle contribute to energy production? How does oxidative phosphorylation generate large amounts of ATP? Why is efficient cellular respiration important for endurance exercise? Part II: Flow Chart Create a flowchart illustrating the metabolic pathways relevant to these processes. You can use the sketch function in the text editor to help create the flow chart. Focus on explaining how metabolic pathways work together to produce energy for cellular and physical activity.