energy systems Flashcards
What is ATP?
- Adenosine triphosphate
The only usable form of chemical energy in the body.
what happens in the ATP-PC/alactic system
- phosphocreatine is used as a fuel to resynthesises ATP
- when ATP is broken down by the enzyme ATPase, ADP is left along with an inorganic phosphate and energy.
- This energy is used for muscle contraction
- Then PC is broken down by creatine kinase (when ATP levels fall) to form creatine, a phosphate ion and energy.
- This then enables resynthesis of ATP so that more energy can be made.
Advantages of the ATP-PC system
- ATP can be resynthesised quickly
- no fatiguing by-products
- PC stores can be re-synthesised quickly (3 mins= 100%) -> quick recovery?
- enables quick and powerful energy
- it is possible to extend the time the ATP-PC system can be utilised through the use of creating supplementation
Disadvantages of the ATP-PC system
- only a limited store of PC in the muscle cell (can only last up to 8 seconds)
- only one mole of ATP can be resynthesised for every mole of PC
- PC re-synthesis can only take place in the presence of oxygen
what is the fuel for the ATP-PC system?
phosphocreatine
what is the reaction site for the ATP-PC system?
the sarcoplasm
what is glycolysis?
The process which breaks down glucose into pyruvic acid
what is lactate dehydrogenase?
The enzyme that converts and buffers pyruvic acid into lactic acid
what is phosphofructokinase
The enzyme that breaks down glucose into pyruvic acid
summary of the method of the lactic acid system
- muscle/liver glycogen is broken down by glycogen phosphate into glucose.
- glucose is then broken down in the process of glycolysis by the enzyme phosphofructokinase into pyruvic acid -> this produces 2 ATP
- Pyruvic acid is then broken down by lactate dehydrogenase into lactic acid
what is the fuel used for the lactate anaerobic system?
glucose/glycogen
site of reaction for the lactate anaerobic system
sarcoplasm
how many moles of ATP are produced per mole of fuel? in the lactate anaerobic system
2
what is the lactate threshold?
The point during exercise at which lactic acid quickly accumulates in the blood. It is where the predominant energy system switches from aerobic to anaerobic
what is lactate sampling?
a process that can measure the accumulation of lactic acid in the blood.
what are the 5 factors which affect lactate accumulation
1) exercise intensity
2) muscle fibre type - slow twitch muscle fibres break down glycogen more efficiently and therefore produce less lactic acid
3) rate of blood lactate removal - if it is being removed at the same rate that it is being produced, levels will remain constant
4) respiratory exchange ratio - the ratio of CO2 produced compared to o2 consumed
5) fitness of the performer - trained performer has increased myoglobin content, mitochondrial density allowing a greater aerobic capacity and delaying the lactate threshold.