Anaerobic energy provision

What happens when ATP is broken down?

• ATP → ADP + Pi + free energy

• This reaction is hydrolysed by the enzyme ATPase

• This reaction releases the high energy bond between the phosphates

How is energy made for muscle contraction?

• ATP is hydrolysed by myofibril ATPase, which is located on the myosin head

• This causes the power stroke to occur, and the filaments to slide over each other

What are the 3 main ATP synthesis pathways?

1. ATP-PCr system (anaerobic metabolism)

2. Glycolytic system (anaerobic metabolism)

3. Oxidative system (aerobic meabolism)

How can you test for Glycolytic system fitness?

• Blood lactate test because glucose is split into pyruvate and lactate during exercise

How can you test for oxidative system fitness?

• VO2 Max test

• RER

How does the ATP-PCr system work?

• Phosphocreatine is broken down by creatine kinase into creatine and a phosphate

• This phosphate is then assembled with ADP, making ATP

• This ATP can then be used for energy

What happens to ATP restoration throughout different exercise intensities?

• The different pathways work well to maintain the same level of muscle ATP

• This level of ATP only drops when intensity has a large increase

Why can creatine supplementation harm performance?

• Creatine has osmotic activity, causing a higher cell water content

• This leads to weight gain, which can deteriorate certain athletes such as sprinters

What is the myokinase reaction?

• ADP + ADP → ATP + AMP (at the cost of 31 kJ/mol)

• This is only carried out during high intensities, and when pH falls

• AMP is an activator of enzymes involved in glycogen breakdown to detect when energy levels are low

How does the anaerobic glycolytic system work?

• Glucose/Glycogen is broken down through glycolysis

• Glucose yields 2 ATP per molecule, and Glycogen yields 3 ATP per molecule

• Takes between 15 seconds to 2 minutes

What will measures of high PFK mean in glycolysis?

This means the athlete produce lots of pyruvate, which can then be converted into lactate

What will measures of high Citrate synthase and SDH mean in the kreb cycle?

This means that the athlete is well equipped to run the kreb cycle because they can sustain aerobic ATP production

What are the muscle fibres enzyme activities (table)

What is ATP power and which system has the greatest?

• The rate at which ATP can be produced

• ATP-PCr system has the greatest power

What is ATP capacity and which system has the greatest?

• How much ATP can be produced

• Oxidative system from fat has the greatest capacity

What is the wingate test?

• 30 second all out effort on a bike

• Usually an applied load of 7.5% of body mass

• Test is used to determine peak power, mean power, and fatigue index

What is the equation for fatigue index?

((Peak power - lowest power) / peak power ) x 100

What are the energy sources during the wingate test?

• Starting 5 seconds is ATP-PCr system

• Majority of the test is the glycolytic system

• Final part will be carried out by the oxidative system

How is ATP turnover calculated?