Ex. phys. A past paper questions Flashcards
Athletes of any age need to maintain a balanced diet high in carbohydrates. How are carbohydrates
stored and transported in the body? (1 mark)
- Carbohydrates are stored in the body in the form of glycogen (in the liver and muscles), and as
glucose (in the blood). Excess carbohydrates are stored as adipose tissue. - They are transported as glucose in the blood.
Explain the concept of ‘hitting the wall’. (1 mark)
EITHER
* Hitting the wall is when an athlete experiences a relatively sudden fatigue, decrease in power
output and an inability to improve their output.
OR
* This is a result of muscle and liver glycogen stores being depleted and fats becoming the
primary fuel source.
Explain glycogen sparing and how an endurance athlete may take advantage of this chronic training
adaptation. (2 marks)
- An athlete’s ability, particularly early in a bout of exercise, to utilise fats to produce ATP,
essentially sparing glycogen, which delays glycogen depletion - Meaning they have more glycogen in reserve to work at higher intensities for longer periods of
time, at a later stage in an event.
Table 1 below shows the men’s World Record times and corresponding average speeds in a number of
running events.
Event World Record Time Average Speed
100m 9.58s 10.44m/s
800m 1min 40.91s 7.93m/s
1500m 3min 26.00s 7.28m/s
42km Marathon 2hr 1min 39.00s 5.78m/s
Peter Bol is an Australian 800-metre runner and Brett Robinson is an Australian marathon runner. With
reference to Table 1, explain the difference in energy system interplay for the two athletes in their
events. (3 marks)
800m runner: The ATP-PC system would supply the least amount of energy for the event, perhaps
for a sprint finish. Then the lactic acid system would supply the majority of ATP for the remainder
of the event as it lasts up to 2 minutes and the WR is 1.40.91. The aerobic system would provide
the second most energy, although because of the elite level, it may provide the most as it could
start supplying energy from as early as 30 seconds. (1 ½ marks)
* The marathon runner: They also use the ATP-PC system the least, perhaps at the start and end of
the race. Then the lactic acid system would supply a small amount, although more than the ATP-PC
system; perhaps for surges and when going up hills and the race for a longer sprint to the line. The
aerobic system will be the predominant supplier of ATP based on the WR time of 2hrs 1minute and
39secs. This system supplies ATP for activities lasting longer than 3-5mins at a submaximal
intensity. (1 ½ marks)
Table 1 below shows the men’s World Record times and corresponding average speeds in a number of
running events.
Event World Record Time Average Speed
100m 9.58s 10.44m/s
800m 1min 40.91s 7.93m/s
1500m 3min 26.00s 7.28m/s
42km Marathon 2hr 1min 39.00s 5.78m/s
Why would the main energy system used by Brett Robinson (marathon runner) not be useful to a 100m track sprinter?
Which energy system would be most useful to a 100m sprinter and what is its source of fuel?
(2 marks)
- The aerobic system is suitable for sub-maximal efforts.
- The 100m will require a maximal effort and the aerobic system will be unable to provide energy
quickly enough. The ATP-PC system would be most suitable for the 100m. Stored ATP for initial
burst then Creatine Phosphate is split to provide energy rapidly in this system.
Explain the energy production process of the energy system that is utilised most in rowing.
(3 marks)
The aerobic system would be producing the majority of the energy through the complete breakdown
of glucose, fats or proteins in the mitochondria in three stages:
* Stage one - glycolysis (breakdown of glycogen). Glycogen is converted to glucose, then some ATP is
created as glucose is converted to pyruvic acid. With the presence of oxygen pyruvic acid enters
stage two.
* Stage two - the Krebs’ Cycle where further ATP is produced and carbon dioxide is a by-product.
* Stage three - the Electron Transport Chain, which generates H2O, heat and CO2 as a by-product.
This is where the majoiry of ATP is produced.
The interplay of the circulatory and respiratory systems is crucial in delivery of oxygen to the working
muscles of all athletes. How does myoglobin assist in this process? (1 mark)
- Myoglobin is a protein based binding agent to which oxygen attaches so it can travel from the
bloodstream through the cell membrane into the mitochondria.
An endurance athlete is able to generate more energy aerobically. Why is the production of energy
more efficient aerobically rather than anaerobically? (1 mark)
- The production of energy is more efficient aerobically as the aerobic system produces no fatiguing
by-products.
When ATP is produced anaerobically lactic acid begins to accumulate. Explain the Lactate Inflection
Point (LIP) and the effect of this on fatigue. (3 marks)
- The Lactate Inflection Point is the last point where the lactate entry into the blood and lactate
removal from the blood is balanced
OR - The point beyond which a given exercise intensity cannot be maintained by the athlete (also
known as lactate threshold) - Beyond this point there is an onset of fatigue, and the time until exhaustion is dependent on the
intensity of the exercise. - The higher the intensity of the exercise the shorter the time until exhaustion due to the
accumulation of lactate and hydrogen ions.
Athletes who feel tired and exhausted may be exercising above their LIP and accumulating lactic acid.
Discuss the processes involved in lactic acid removal. (2 marks)
- Lactic acid removal needs to occur when lactic acid accumulates during exercise. Some LA is used
by the heart and other skeletal muscles and converted back into pyruvic acid and then
metabolised back into ATP so it can be a further source of energy. - Immediately after exercise LA can be converted back into glycogen by the liver. The mitochondria
converts some LA to carbon dioxide and water if there is sufficient oxygen, some to protein and
some to glucose.
OR - 65% is oxidised to form cardon dioxide and water
- 20% is converted back into glucose by the loiver. This is returned tot he liver and muscles to be
stored as glycogen. - 10% is converted in the liver to form protein.
- 5% is converted into glucose.
Explain one of the processes of energy production that is utilised when oxygen is not available or an
athlete’s energy demands are high. (3 marks)
Either the ATP-PC System:
* The ATP-PC System uses an anaerobic process that occurs in the muscle cell. ATP is produced
first by ATP splitting and then through the breakdown of PC.
* ATP splitting occurs when one of the three phosphate bonds is broken. When PC bonds are
broken the phosphate re-joins with the ADP left from the ATP splitting and therefore more
energy can be produced.
* This is the predominant energy system for maximal intensity efforts lasting up to 10 seconds.
or Lactic Acid System:
* The LA system uses an anaerobic process where energy is released from the incomplete breakdown glucose. Glycogen is changed into a form of glucose and sent through glycolysis. The substance generated at the end is pyruvic acid.
* Without oxygen present excess pyruvic acid is then converted into lactic acid and hydrogen ions.
* This is the predominant energy system for near maximal efforts lasting between 10-30 seconds.
What is oxygen deficit? How does this affect a participant’s energy production in the early stages of a
marathon? (2 marks)
- Oxygen deficit is the difference between the amounts of oxygen required for a task (had all the energy been supplied aerobically) and the amount the body was able to supply, up until the point where a steady state is achieved
OR - Oxygen deficit is the state in which there is a discrepancy (shortfall) between oxygen supply and use and the oxygen required to meet the energy demands of the activity; under these conditions the anaerobic pathways must supplement the energy demands of the activity.
- This especially occurs in the first few minutes of a marathon as participants suddenly increase their
intensity of effort, and need to rely on their anaerobic systems to meet energy demands.
Would participants reach a ‘steady state’ during a 3000m run? Justify your answer. (1 mark)
- Steady state is where oxygen demand is equal to the oxygen supplied so as the run lasts over 3
minutes then, yes, they would.
state the products and byproducts of the krebs cycle and electron transport chain.
krebs: co2, H+, atp
electron transport chain: H2o, atp, heat
Explain the term maximal oxygen consumption (VO2 max). (1 mark)
- Maximum oxygen consumption (VO2 max) is the maximum amount of oxygen that can be taken in
and utilised by the body to produce energy during maximal or exhaustive exercise.
