Energy systems Flashcards
Explain the role of ATP in providing energy for muscular contraction
The only usable form of energy in the human body / energy currency
High energy phosphate compound / the phosphate bonds are high energy bonds / a store of potential energy
When the phosphate bond is broken energy is released / ATP is broken down to release energy / ATP → ADP + P + ENERGY
An exothermic reaction
Facilitating enzyme is ATPase
Can be resynthesised (via the energy systems / with or without oxygen)
The breakdown and resynthesis of ATP is a reversible reaction or
ATP ↔ ADP + P + ENERGY
Explain why ATP plays a major role in the performance of a smash in badminton (2 marks)
(Duration) ATP breakdown provides energy for immediate need / up to 2 seconds / releases energy quickly
(Intensity) ATP breakdown provides energy for explosive / powerful / (very) high-intensity
What is a coupled reaction and how does it work with ATP
Coupled reaction: The products of one reaction are used in another reaction
The continual breakdown and resynthesis of ATP is known as a coupled reaction
Energy produced from the breakdown of ATP can be used to resynthesise another molecule of ATP.
Description of ATP-PC system
Type of reaction: Anaerobic
Site of reaction: Sarcoplasm
Food fuel used: Phosphocreatine (PC)
Controlling enzyme: Creatine Kinase
ATP yield: 1 mole of PC yields 1 mole of ATP (1:1)
Specific stages: PC = P + C + energy (exothermic)
Energy + P + ADP = ATP (endothermic)
Bi-products: None
Intensity of activity: Very high intensity
Duration of system: 2 – 10 seconds
Strengths of ATP-PC system
Strengths:
No delay for oxygen
PC readily available in the muscle cell
Simple and rapid breakdown of PC and resynthesis of ATP
Provides energy for very high intensity activities
No fatiguing by-products and simple compounds aid fast recovery
Weaknesses of ATP-PC system
Weaknesses:
Low ATP yield and small PC stores lead to rapid fatigue after 8-10 seconds
Description of the glycolytic system
Type of Reaction: Anaerobic
Site of Reaction: Sarcoplasm
Food Fuel Used: Glycogen/ Glucose
Controlling Enzyme: GPP, PFK and LDH
ATP yield: 1: 2 1 mole of glycogen yields 2 moles of ATP
Stage 1: Anaerobic Glycolysis: Glycogen/glucose = Pyruvic Acid + energy
Stage 2: Lactate Pathway: Pyruvic Acid = Lactic Acid
ATP resynthesis: Energy + 2P + 2ADP = 2ATP (endothermic)
By-products: Lactic Acid
Intensity of activity: High Intensity
Duration: Up to 3 minutes depending on intensity
Strengths of glycolytic system
- No delay for O2
- Large stores of glycogen in the liver and muscles
- Good stores of glucose in the bloodstream
- Relatively fast breakdown for ATP resynthesis
- Provides energy for up to 3 minutes
Weaknesses of glycolytic system
- Low energy yield
- Recovery can be lengthy
- Fatiguing by-product reduces pH and enzyme activity which causes muscular cramp and decreases ATP resynthesis
1st stage of aerobic system
Glycogen via GPP goes to glucose which via PFK —> Pyruvate/ Pyruvic
acid
The breakdown of glucose into pyruvate releases enough energy to
resynthesise 2 moles of ATP – this is an exothermic reaction
The pyruvic acid goes through a link reaction which is catalysed by the enzyme coenzyme A which produces acetyl CoA
The link reaction transports the pyruvic acid to the mitochondria in
the cell as this is where stage 2 takes place – the Kreb’s cycle.
2nd stage of aerobic system
Krebs cycle
Acetyl CoA from stage 1 combines with Oxaloacetic acid to form citric acid.
Citric acid is then broken down in a series of complex reactions where four events take place…
CO2 is produced and removed via the lungs
Hydrogen atoms are removed
Energy is produced to resynthesise two more molecules of ATP (total of 4 now)
Oxaloacetic acid is regenerated
3rd stage of aerobic system
Electron transport chain
The hydrogen atoms are carried through the electron transport chain and along the cristae of the mitochondria. They are then split into
Ions (H+) and Electrons (H- or e-)
Hydrogen electrons and ions are oxidised (combine with oxygen) and are removed as H20 (water)
Pairs of Hydrogen electrons carried by NAD (NADH/ NADH2) release
enough energy to resynthesise 30 moles of ATP
Those carried by FAD (FADH2) release enough energy to resynthesise 4 moles of ATP
Description of aerobic system
Type of Reaction: Aerobic
Site of Reaction: Sarcoplasm, Mitochondria Matrix and Cristae
Food Fuel Used: Glycogen, Glucose and Triglycerides (FFAS)
Controlling Enzyme: GPP, PFK, coenzyme A and Lipase
ATP yield: 1:38 - 1 mole of glycogen to 38 moles of ATP
Exothermic Reaction: Glucose (C6 H12O6) + 6O2 6CO2 + 6H2O + energy
Glucose + oxygen = carbon dioxide + water + energy
Endothermic Reaction: Energy + 38P + 38 ADP 38 ATP
By-products: CO2 + H2O – none of these are fatiguing by-products
Intensity of activity: Low – Moderate / sub maximal intensity
Duration: 3 minutes +
Strengths of aerobic system
Large fuel stores; triglycerides, FFA’s, glycogen and glucose
High ATP yield and long duration of energy production
No fatiguing by-products
Weaknesses of aerobic system
Delay for O2 delivery and complex series of reactions
Slow energy production limits activity to sub-maximal intensity
Triglycerides or FFA’s demand around 15% more oxygen for breakdown
What are free fatty acids
FFA’s – are the form which the fatty acid leaves the cell to be transported to another part of the body
They are a HUGE potential fuel store
Lipase can be triggered to be released which can catalyse the breakdown of Triglycerides into FFA’s and glycerol.
FFA’s are then converted into Acetyl CoA and follow the same path thorough the ETC as pyruvic acid
Strengths of free fatty acids
FFA’s produce more Acetyl CoA and have a higher energy yield
This means that they are much more preferred for long distance athletes whose events last longer than 1 hour However, FFA’s require around 15% more oxygen to metabolise (change food into a form that can be used by your body) and consequently, the intensity of the activity must remain low.
1:129 ATP this occurs mostly as we rest/ very low intensity because of the low intensity and long duration!
7 factors affecting relative contribution of energy systems
Availability of oxygen
Fuel availability
Fitness level
Position of the player
Tactics and strategies
Level of competition
Structure of the game
Energy continuum
The relative contribution of each energy system to overall energy
production depending on the intensity and duration of the activity.
Each energy system will rarely work in isolation.
100m example -90% anaerobic
70% - ATP – PC system
20% - Glycolytic system
10 % Aerobic system
