Paper 1 - Energy Systems Flashcards
What do all fuels convert to?
ATP
Adenosine triphosphate
What is ATP?
The only thing that can create energy
Made up of 1 adenosine and 3 phosphate molecules
Explain the break down of ATP
In order to release the energy that is held in the bonds between three phosphate molecules in ATP, one of these bonds must be broken. This chemical reaction is catalysed by ATPase which splits the bond between two of the phosphate molecules to produce ADP (adenosine diphosphate), 1 phosphate molecule and energy. This is called an exothermic reaction.
Explain the re synthesis of ATP
ATP only last for approximately 2 to 3 seconds. We do not have an endless supply of ATP within the body and, therefore, it needs to be re-synthesised after it is broken down, in order to provide more energy in the future. It is resynthesised by using energy to form a bond between a phosphate molecule and ADP. The ATP that is formed will be available to fuel the next burst of high intensity exercise that an athlete performs. This is called an endothermic reaction.
What are the 3 energy systems?
The body must use one of three energy systems to produce the energy which is required to re-synthesise ATP from ADP + P.
ATP-PC (phosphocreatine) system
Glycolytic system
Aerobic system
What is the ATP-PC energy system?
Re-synthesises ATP from breakdown of phosphocreatine.
Predominate during a sudden movement
PC is high in type 2B fibres
What is the glycolytic energy system?
Re-synthesises ATP from the breakdown of glycogen.
What is the aerobic energy system?
Re-synthesises ATP from the breakdown of glycogen, glucose and free fatty acids (FFAs)
Predominate at rest
Summarise the breakdown of ATP as an equation
ATP —ATPase—> ADP + P + Energy
Summarise the ATP-PC system in the form of equations
PC —creatine kinase —> P + C + Energy (EXOTHERMIC)
(Coupled reaction)
Energy + ADP + P -> ATP (ENDOTHERMIC)
What is a coupled reaction
When the products from one reaction such as energy are then used in another reaction
What is an exothermic reaction?
A chemical reaction that releases energy as it progresses
(breakdown of ATP and breakdown of PC)
What is an endothermic reaction?
A chemical reaction that requires energy for it to progress
(Resynthesis of ATP)
Fill in the ATP-PC on the energy systems table
Bamboo paper
ATP-PC : Adaptions to training
Anaerobic training overloads system = increase in muscle stores of ATP and PC
(Examples of anaerobic training = weight training and sprinting)
I
I
This delays threshold and increases potential duration
(e.g. 10 seconds goes to 10.5 or 11 seconds, 1 extra second is very valuable in sprinting, etc)
ATP-PC System : Advantages
Doesn’t require oxygen
PC stored in muscle cell = readily accessible and available
Simple/small compound = quick reaction/resynthesis
Automatically stimulated by decreased ATP levels
No fatiguing products
ATP-PC System : Disadvantages
Only small amount of ATP (2-3s) and PC (10s) stored in muscles and cells
1 PC resynthesis to 1 ATP = very low yield
Only provides energy for up to 10 seconds = cannot be sustained
Fill in the glycolytic system on the energy systems table
Bamboo paper
Describe the resynthesis of ATP via the glycolytic system
The lactic acid system breaks down glucose/glycogen to provide energy via coupled reactions. Anaerobic glycolysis. Glucose is provided directly from digestive carbohydrates/stored glycogen located in the liver and muscle is the decrease of PC stores activates the enzyme glycogen phosphorylase (GPP) to break down glycogen into glucose. Glucose is then broken down into pyruvate (pyruvic acid) by the enzyme phosphofructose kinase (PFK). In the absence of oxygen pyruvate is then converted to lactic acid by lactate dehydrogenase (LDH). The main limitation of the lactic acid system is due to the onset of blood lactate accumulation (OBLA). This accumulation of lactic acid decreases blood pH and therefore inhibits enzymes used in glycolysis. This causes fatigue and can be quite painful. OBLA occurs at 4mmol per litre of blood.
DRAW DIAGRAM LIKE ON BAMBOO PAPER
Glycolytic : Adaptations to training
Anaerobic training, overloads system = increase in body is tolerance (get rid/break down, lactic acid better/quicker) to lactic acid
Increases glucagon store (metabolic adaption)
Delays OBLA (due to tolerance) prolonging, lactic acid threshold (from about 1 minute - 1.5/2 minutes)
Glycolytic : Advantages
Large glycogen stores in muscles/liver = readily available as a potential energy store
Resynthesised 2 ATP = more than ATP-PC system
Fewer reactions than aerobic system = quicker supply of energy
Enzymes are activated as soon as PC levels decrease
Provides energy for high intensity activities for 10 to 180 seconds
Glycolytic : Disadvantages
Not as quick as ATP-PC system
Produces lactic acid, fatiguing product = lower pH = OBLA and enzyme inhibition = stimulation of pain receptors
Net effect = muscle fatigue/tiredness and pain
Fill in the aerobic system on the energy systems table
Bamboo paper