Energy Systems Flashcards
How long does the ATP-PC system last? Eg?
10 secs
Eg usian bolt 100m
Is the ATP-PC system aerobic or anaerobic?
Anaerobic so there is no oxygen
What fuel is used to power ATP resynthesis in the ATP-PC system and where is it stored?
Phosphocreatine
- stored in the muscle cells alongside ATP for rapid access
How is phosphocreatine broken down?
1) ATP is used for muscle contraction
1) the increase of ADP and PI releases creatine kinase
2) creatine kinase breaks down PCr into creatine and phosphate
3) energy is released (exothermic) which is used to resynthesis ADP and PI into ATP in the muscle
4) the ATP is broken down for muscle contraction
What is the coupled reaction?
As soon as ATP is broken down, the energy from PCr break down resynthesis the ATP
What are the three energy systems?
ATP - Pc system
Lactic acid system
Aerobic system
What are the advantages of the ATP-PC system?
- ATP can be resynthesised rapidly in mucked cell
- PCr stored are recovered quickly (50=30 secs)
- no fatiguing by products Eh lactic acid
What are the disadvantages of the ATP-PC system?
- only available for 10 secs
- PCr replenishment can only take place in the presence of oxygen
- only 1 mole of ATP is resynthesised from 1 mole PCr
What is the lactic acid system also known as?
Anaerobic glycolysis
How long does the lactic acid system last? Eg
Lasts for around 60 secs
Eg 400m runner
What is the energy source for the lactic acid system and where does ATP resynthesis take place?
Glycogen (carbohydrate) stored in the muscle and liver
Takes place in the sarcoplasm in the muscle cell
What is the process of lactic acid system?
1) PCr stores run out so glycogen is needed
2) glycogen is converted into glucose-6-phosphate by the enzyme phosophofrutokinase
3) energy is released and makes 2 miles of ATP
4) private acid is produced
5) bc of the lack of oxygen, pyro ate acid is turned into lactic acid by enzyme lactate dehydrogenase
What is glycolysis?
Breaking down of glycogen to pyruvate acid by PFK
What are the advantages of the lactic acid system?
- doesn’t need the presence of oxygen to work
- lactic acid can be converted back into glycogen and pyruvate in the liver and can be used in the aerobic system
- can be used for sprint finishes / bursts of energy
What are the disadvantages of the lactic acid system?
- lactic acid stops energy production as it stops enzymes from working (denatures PFK so glycogen can’t be broken down)
- lactic acid means that intensity must be reduced
- only a small amount of energy can be released
What energy source is used in the aerobic system?
Glycogen = 55% Fats = 30% Proteins = 10%
When is the aerobic system used? Eg
During rest and moderate intense exercise where oxygen is available
Eg marathon - Mo Farrah
What are the 3 stages of the aerobic system?
1) aerobic glycolysis
2) Krebs cycle
3) electron transport chain (ETC)
What happens in the first stage of the aerobic system?
1) the glycogen is broken down by PFK into g-6-p and then turns into pyruvate acid
2) bc there is oxygen, pyruvate acid combines with coenzyme A and turns into acetyl coenzyme A
3) now moves from the sarcoplasm to the mitochondria
What happens in 2nd stage of aerobic system?
1) it enters the Kreb cycle in the mitrochondria
2) acetyl coenzyme A combined with oxaloacetic to make citric acid
3) the citric acid is oxidised to from hydrogen, carbon dioxide and 2 ATP moles
4) co2 is sent to the lungs and hydrogen is sent to the ETC
What happens in the 3rd stage of the aerobic system?
The hydrogen atoms split and give off water and 34 moles of ATP
How much more energy is made in the aerobic than anaerobic system?
18 times
36 moles of ATP
How are the 3 fuels in the aerobic system used?
Glycogen - glycolysis
Fats - beta oxidisation turns them into fatty acids and then ACoA
Proteins - turns into amino acids and then ACoA
What are the advantages of the aerobic system?
- more ATP can be resynthesised
- body has large amount of fat and glycogen so exercise can last for a long time
- doesn’t produce any fatiguing by-products
What are the disadvantages of the aerobic system?
- takes a while for sufficient oxygen to become available so can’t be used short term
- fatty acids requires 15% more oxygen in order to break them down into ACoA
- fats can only be broken down in the presence of glycogen. Limited amounts can cause spasm of the muscles
