BIOENERGETICS & ENERGY TRANSFER

Question 1

Major energy (ATP) production processes

Answer 1

Phosphagen System (ATP-PC): Uses creatine phosphate for immediate ATP (0-10 seconds, e.g., heavy lifting).

Glycolysis (Anaerobic): Breaks down glucose into ATP (10 seconds to 2 minutes, e.g., sprinting).

Oxidative Phosphorylation (Aerobic): Uses carbs, fats, and sometimes proteins for sustained ATP production (>2 minutes, e.g., endurance events).

Question 2

Know the major rate limiting enzymes in the glycolysis and FA metabolism

Answer 2

Glycolysis: Phosphofructokinase (PFK) controls the rate of glycolysis.

Fat Metabolism (Beta-Oxidation): Carnitine palmitoyltransferase I (CPT I) regulates the transport of fatty acids into mitochondria.

Question 3

Describe the predominant energy systems utilized during different activities of different durations (picking up heavy objects (resistance exercise), sprinting, versus long duration endurance events)

Answer 3

Resistance Exercise: Phosphagen system (short, intense bursts of energy using creatine phosphate).

Sprinting: Glycolysis (short duration with glucose breakdown).

Endurance Events: Oxidative Phosphorylation (longer durations with aerobic metabolism of fats and carbs).

Question 4

Lactate threshold and the metabolic use of lactate (Cori cycle)

Answer 4

Lactate Threshold: Point at which lactate accumulation exceeds clearance, causing fatigue (often around 50-80% VO2 max).

Cori Cycle: Converts lactate from muscles to glucose in the liver, which can be reused for energy.

Question 5

Describe the relationship between oxygen consumption and ATP demands

Answer 5

Oxygen Consumption: Increases with ATP demands. During exercise, oxygen is required for aerobic ATP production, and the body adapts by increasing oxygen intake.

Question 6

Describe the different factors that influence oxygen deficit and EPOC (excess post exercise oxygen consumption

Answer 6

Oxygen Deficit: The initial gap where ATP demand exceeds oxygen supply at the start of exercise (metabolism is anaerobic).

EPOC: Elevated oxygen consumption after exercise to restore energy stores, clear lactate, and return to baseline. Factors influencing EPOC include intensity, duration, and fitness level.