What are the three energy systems?

What are the three energy systems?

• A. ATP/PC; Glycolytic or lactic acid; Aerobic or Oxidative
• B. NADH; FAD; ATP
• C. Carbohydrate metabolism; Lipid metabolism; Protein metabolism
• D. Phosphocreatine; Adenosine; Glucose

Answer: (A)

The main idea is how ATP is regenerated to fuel work across different intensities and durations. The first system, the phosphagen (ATP-PC) system, uses stored phosphocreatine to rapidly replenish ATP for very brief, high-intensity efforts—think quick sprints or explosive movements lasting up to about 10 seconds. The second system, the glycolytic (lactic acid) system, breaks down glucose or glycogen to produce ATP without needing oxygen, and it tends to dominate activities that last from roughly 10 seconds to a couple of minutes, often producing lactate as a by-product. The third system is the oxidative (aerobic) system, which requires oxygen and uses carbohydrates and fats (and to a lesser extent amino acids) to generate ATP for longer-duration activity; it has a slower onset but the greatest overall capacity. The three terms listed correspond directly to these distinct energy pathways. The other options mix up molecules or substrates that aren’t the separate energy systems themselves.

The main idea is how ATP is regenerated to fuel work across different intensities and durations. The first system, the phosphagen (ATP-PC) system, uses stored phosphocreatine to rapidly replenish ATP for very brief, high-intensity efforts—think quick sprints or explosive movements lasting up to about 10 seconds. The second system, the glycolytic (lactic acid) system, breaks down glucose or glycogen to produce ATP without needing oxygen, and it tends to dominate activities that last from roughly 10 seconds to a couple of minutes, often producing lactate as a by-product. The third system is the oxidative (aerobic) system, which requires oxygen and uses carbohydrates and fats (and to a lesser extent amino acids) to generate ATP for longer-duration activity; it has a slower onset but the greatest overall capacity. The three terms listed correspond directly to these distinct energy pathways. The other options mix up molecules or substrates that aren’t the separate energy systems themselves.