SmarterEd

Aussie Maths & Science Teachers: Save your time with SmarterEd

HMS, BM 2013 HSC 18 MC*

What is a common feature of both the alactacid (ATP-PCr) and lactic acid energy systems?

  1. Lactic acid is produced.
  2. ATP is resynthesised anaerobically.
  3. Both systems take the same period of time to recover.
  4. The accumulation of lactic acid in the working muscles causes fatigue.
Show Answers Only

\(B\)

Show Worked Solution

NOTE: This question has been updated to include the HMS system naming of the alactacid system with ATP-PCr.

  • B is correct: Both alactacid (ATP-PCr) and lactic acid systems operate without oxygen.

Other Options:

  • A is incorrect: Only lactic acid system produces lactic acid.
  • C is incorrect: Systems have different recovery time periods significantly.
  • D is incorrect: Only lactic acid system causes fatigue through accumulation.

♦♦ Mean mark 52%.

HMS, BM 2014 HSC 27

Compare the two anaerobic energy systems.   (5 marks)

Show Answers Only

ATP-PCr system and Glycolytic (Lactic Acid) system

Similarities:

  • Both systems operate without oxygen during anaerobic metabolism processes.
  • Both provide energy for high-intensity, short-duration explosive activities.
  • Both systems work together during power-based movements like sprinting.
  • Both use stored energy sources available within muscle tissue.
  • Both produce ATP for immediate muscular contraction requirements.

Differences:

  • ATP-PCr uses stored phosphocreatine whilst glycolytic system uses muscle glycogen and glucose.
  • ATP-PCr operates for 10-15 seconds maximum, glycolytic system functions 15 seconds to 2 minutes.
  • ATP-PCr produces ATP most rapidly but glycolytic system has greater total capacity.
  • ATP-PCr fatigues when phosphocreatine stores deplete, glycolytic fatigues from lactate accumulation.
  • ATP-PCr recovers completely in 2-3 minutes, glycolytic requires longer recovery periods.
  • ATP-PCr produces no fatiguing by-products, glycolytic creates lactate causing muscle burn.

Summary:

  • ATP-PCr provides immediate explosive power whilst glycolytic sustains high-intensity efforts for longer periods.
Show Worked Solution

ATP-PCr system and Glycolytic (Lactic Acid) system

Similarities:

  • Both systems operate without oxygen during anaerobic metabolism processes.
  • Both provide energy for high-intensity, short-duration explosive activities.
  • Both systems work together during power-based movements like sprinting.
  • Both use stored energy sources available within muscle tissue.
  • Both produce ATP for immediate muscular contraction requirements.

Differences:

  • ATP-PCr uses stored phosphocreatine whilst glycolytic system uses muscle glycogen and glucose.
  • ATP-PCr operates for 10-15 seconds maximum, glycolytic system functions 15 seconds to 2 minutes.
  • ATP-PCr produces ATP most rapidly but glycolytic system has greater total capacity.
  • ATP-PCr fatigues when phosphocreatine stores deplete, glycolytic fatigues from lactate accumulation.
  • ATP-PCr recovers completely in 2-3 minutes, glycolytic requires longer recovery periods.
  • ATP-PCr produces no fatiguing by-products, glycolytic creates lactate causing muscle burn.

Summary:

  • ATP-PCr provides immediate explosive power whilst glycolytic sustains high-intensity efforts for longer periods.

♦♦ Mean mark 54%.

HMS, BM 2017 HSC 25

Compare TWO different energy systems by exploring their duration, sources of fuel and causes of fatigue. Use examples to support your answer.   (7 marks)

Show Answers Only

Energy Systems Being Compared:

  • ATP-PCr System (Phosphocreatine System)
  • Aerobic System (Oxidative System)

Similarities

  • Both energy systems produce ATP to fuel muscle contractions during exercise activities. They work together seamlessly during most physical activities to meet energy demands.
  • Both systems can operate without requiring external oxygen supply from the respiratory system. This allows immediate energy production when exercise begins before breathing rate increases.

Differences – Duration

  • The ATP-PCr system operates for very short durations of 10-15 seconds maximum. This occurs because stored ATP and creatine phosphate supplies are limited in muscle cells.
  • The aerobic system functions for hours or even days. This happens because oxygen allows continuous fuel breakdown without harmful byproduct accumulation.

Differences – Fuel Sources

  • The ATP-PCr system sources fuel from stored ATP and creatine phosphate already present in muscles. This enables immediate energy release without requiring glucose breakdown.
  • The aerobic system utilises carbohydrates, fats and proteins as fuel sources.  This process requires oxygen to completely break down these substrates.

Differences – Causes of Fatigue

  • Fatigue in the ATP-PCr system results from depletion of stored phosphocreatine reserves. For instance, a weightlifter cannot continue once stores are exhausted.
  • Aerobic system fatigue occurs due to fuel depletion or oxygen limitations. Marathon runners experience this when glycogen stores become depleted.
Show Worked Solution

Energy Systems Being Compared:

  • ATP-PCr System (Phosphocreatine System)
  • Aerobic System (Oxidative System)

Similarities

  • Both energy systems produce ATP to fuel muscle contractions during exercise activities. They work together seamlessly during most physical activities to meet energy demands.
  • Both systems can operate without requiring external oxygen supply from the respiratory system. This allows immediate energy production when exercise begins before breathing rate increases.

Differences – Duration

  • The ATP-PCr system operates for very short durations of 10-15 seconds maximum. This occurs because stored ATP and creatine phosphate supplies are limited in muscle cells.
  • The aerobic system functions for hours or even days. This happens because oxygen allows continuous fuel breakdown without harmful byproduct accumulation.

Differences – Fuel Sources

  • The ATP-PCr system sources fuel from stored ATP and creatine phosphate already present in muscles. This enables immediate energy release without requiring glucose breakdown.
  • The aerobic system utilises carbohydrates, fats and proteins as fuel sources.  This process requires oxygen to completely break down these substrates.

Differences – Causes of Fatigue

  • Fatigue in the ATP-PCr system results from depletion of stored phosphocreatine reserves. For instance, a weightlifter cannot continue once stores are exhausted.
  • Aerobic system fatigue occurs due to fuel depletion or oxygen limitations. Marathon runners experience this when glycogen stores become depleted.

♦♦ Mean mark 55%.

HMS, BM 2024 HSC 22

Compare the by-products of TWO different energy systems.   (4 marks)

Show Answers Only

Sample Answer

Similarities:

  • Both ATP-PCr and glycolytic systems produce by-products during ATP generation.
  • Both by-products must be managed by the body for continued performance.

Differences:

  • ATP-PCr produces creatine and phosphate which cause no muscle fatigue or performance impairment.
  • Glycolytic system generates lactic acid which creates burning sensation and impairs muscle contraction.
  • ATP-PCr by-products remain in muscle cells for immediate reconversion within minutes.
  • Lactic acid must be transported via bloodstream to the liver for removal, taking much longer.
  • Chemical nature determines impact: harmless phosphates versus performance-limiting acid.
Show Worked Solution

Sample Answer

Similarities:

  • Both ATP-PCr and glycolytic systems produce by-products during ATP generation.
  • Both by-products must be managed by the body for continued performance.

Differences:

  • ATP-PCr produces creatine and phosphate which cause no muscle fatigue or performance impairment.
  • Glycolytic system generates lactic acid which creates burning sensation and impairs muscle contraction.
  • ATP-PCr by-products remain in muscle cells for immediate reconversion within minutes.
  • Lactic acid must be transported via bloodstream to the liver for removal, taking much longer.
  • Chemical nature determines impact: harmless phosphates versus performance-limiting acid.

HMS, BM EQ-Bank 765

Explain how causes of fatigue differ between the ATP-PCr system and the glycolytic system during high-intensity exercise.   (4 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system experiences fatigue solely from phosphocreatine depletion after 10-15 seconds of maximal effort.
  • This occurs because stored PCr becomes exhausted without producing any fatiguing by-products.
  • Heat is the only by-product, which enables rapid recovery within 2 minutes.
  • Therefore, ATP-PCr fatigue is temporary and quickly reversible.
  • The glycolytic system fatigues due to lactic acid accumulation in muscle cells.
  • Lactic acid forms when glucose breaks down anaerobically, accumulating faster than removal rates.
  • As a result, the acid interferes with enzyme function and muscle contraction.
  • Consequently, glycolytic fatigue persists longer, requiring 30-60 minutes for complete recovery.
Show Worked Solution

Sample Answer 

  • The ATP-PCr system experiences fatigue solely from phosphocreatine depletion after 10-15 seconds of maximal effort.
  • This occurs because stored PCr becomes exhausted without producing any fatiguing by-products.
  • Heat is the only by-product, which enables rapid recovery within 2 minutes.
  • Therefore, ATP-PCr fatigue is temporary and quickly reversible.
  • The glycolytic system fatigues due to lactic acid accumulation in muscle cells.
  • Lactic acid forms when glucose breaks down anaerobically, accumulating faster than removal rates.
  • As a result, the acid interferes with enzyme function and muscle contraction.
  • Consequently, glycolytic fatigue persists longer, requiring 30-60 minutes for complete recovery.

HMS, BM EQ-Bank 188

Compare the causes of fatigue between a 400 metre sprint and a marathon runner.   (4 marks)

Show Answers Only

Sample Answer

Similarities:

  • Both events cause fatigue that limits performance and forces athletes to slow down.
  • Both require recovery time before the athlete can perform at the same level again.

Differences:

  • The 400m sprint causes rapid lactic acid build-up from anaerobic glycolysis, making muscles acidic within 45 seconds.
  • Marathon running depletes glycogen stores after about 2 hours, forcing inefficient fat use.
  • Sprint fatigue includes immediate burning sensations and muscle tightness.
  • Marathon fatigue involves gradual energy loss, dehydration and overheating.
  • Sprint fatigue clears within an hour while marathon recovery takes days.
Show Worked Solution

Sample Answer

Similarities:

  • Both events cause fatigue that limits performance and forces athletes to slow down.
  • Both require recovery time before the athlete can perform at the same level again.

Differences:

  • The 400m sprint causes rapid lactic acid build-up from anaerobic glycolysis, making muscles acidic within 45 seconds.
  • Marathon running depletes glycogen stores after about 2 hours, forcing inefficient fat use.
  • Sprint fatigue includes immediate burning sensations and muscle tightness.
  • Marathon fatigue involves gradual energy loss, dehydration and overheating.
  • Sprint fatigue clears within an hour while marathon recovery takes days.

HMS, BM EQ-Bank 165

Compare and contrast how the ATP-PCr and glycolytic energy systems respond to high intensity exercise.   (4 marks)

Show Answers Only

Similarities

  • Both systems operate anaerobically, providing ATP without oxygen during maximal efforts.
  • Both support high-intensity exercise when oxygen cannot meet demands.

Differences

  • ATP-PCr activates instantly for 10-15 seconds while glycolytic takes time to reach peak output.
  • ATP-PCr produces harmless creatine whereas glycolytic generates performance-limiting lactic acid.
  • Recovery differs greatly: PCr replenishes rapidly within minutes versus much longer for lactic acid clearance.
  • ATP-PCr suits explosive single efforts like jumps while glycolytic sustains repeated high-intensity work for 30-90 seconds.
Show Worked Solution

Similarities

  • Both systems operate anaerobically, providing ATP without oxygen during maximal efforts.
  • Both support high-intensity exercise when oxygen cannot meet demands.

Differences

  • ATP-PCr activates instantly for 10-15 seconds while glycolytic takes time to reach peak output.
  • ATP-PCr produces harmless creatine whereas glycolytic generates performance-limiting lactic acid.
  • Recovery differs greatly: PCr replenishes rapidly within minutes versus much longer for lactic acid clearance.
  • ATP-PCr suits explosive single efforts like jumps while glycolytic sustains repeated high-intensity work for 30-90 seconds.

HMS, BM EQ-Bank 157

How does the efficiency of ATP production differ between the glycolytic and aerobic systems?    (5 marks)

Show Answers Only
  • When glucose breaks down without oxygen, the glycolytic system only partly breaks down the fuel, resulting in lactic acid build-up.
  • This happens because glucose cannot be fully broken down, leaving much energy still trapped in lactic acid.
  • As lactic acid increases, it makes muscles more acidic, which causes enzymes to work poorly and forces athletes to slow down within 30–90 seconds.
  • In contrast, when oxygen is available, the aerobic system completely breaks down glucose in the mitochondria, producing much more ATP per glucose molecule.
  • This creates only carbon dioxide, water and heat as by-products, which are removed easily without causing fatigue.
  • The aerobic system’s better efficiency allows energy production for hours, though at a slower rate than glycolysis.
  • Therefore, the intensity and duration of an activity determine whether glycolytic speed or aerobic efficiency predominates.
Show Worked Solution
  • When glucose breaks down without oxygen, the glycolytic system only partly breaks down the fuel, resulting in lactic acid build-up.
  • This happens because glucose cannot be fully broken down, leaving much energy still trapped in lactic acid.
  • As lactic acid increases, it makes muscles more acidic, which causes enzymes to work poorly and forces athletes to slow down within 30–90 seconds.
  • In contrast, when oxygen is available, the aerobic system completely breaks down glucose in the mitochondria, producing much more ATP per glucose molecule.
  • This creates only carbon dioxide, water and heat as by-products, which are removed easily without causing fatigue.
  • The aerobic system’s better efficiency allows energy production for hours, though at a slower rate than glycolysis.
  • Therefore, the intensity and duration of an activity determine whether glycolytic speed or aerobic efficiency predominates.

HMS, BM EQ-Bank 145

How do the by-products and recovery rates differ between the ATP-PCr and Lactic Acid energy systems?    (4 marks)

Show Answers Only

Sample Answer

  • When ATP-PCr breaks down, it releases creatine and phosphate which cause no muscle impairment, enabling immediate reuse.
  • This allows rapid recovery because phosphate simply recombines with creatine, restoring 50% of PCr stores within 30 seconds.
  • Full PCr restoration occurs through this simple recombination process, completing within 2 minutes.
  • Conversely, when the glycolytic system operates without oxygen, it produces lactic acid which leads to lowered muscle pH and impaired contraction.
  • Lactic acid removal follows a complex pathway: first diffusing into blood, then transported to the liver for conversion back to glucose.
  • As a result, complete lactic acid clearance requires 30-60 minutes compared to just 2 minutes for full PCr restoration.
Show Worked Solution

Sample Answer

  • When ATP-PCr breaks down, it releases creatine and phosphate which cause no muscle impairment, enabling immediate reuse.
  • This allows rapid recovery because phosphate simply recombines with creatine, restoring 50% of PCr stores within 30 seconds.
  • Full PCr restoration occurs through this simple recombination process, completing within 2 minutes.
  • Conversely, when the glycolytic system operates without oxygen, it produces lactic acid which leads to lowered muscle pH and impaired contraction.
  • Lactic acid removal follows a complex pathway: first diffusing into blood, then transported to the liver for conversion back to glucose.
  • As a result, complete lactic acid clearance requires 30-60 minutes compared to just 2 minutes for full PCr restoration.