1.5 Energy Systems Flashcards
What does ATP stand for?
Adenosine Tri-Phosphate.
In what form are carbohydrates stored in the body?
Carbs are stored as glycogen.
Where is glycogen stored in the body?
In the liver and the muscles.
What is the role of glycogen during exercise?
It is converted into glucose during exercise.
How are fats stored in the body?
As triglycerides.
What is the function of triglycerides during exercise?
They are converted into free fatty acids when required.
When is protein used as energy?
When glycogen stores are running extremely low.
What is ATP?
The usable form of energy in the body.
What does an ATP molecule consist of?
An ATP molecule consists of adenine and 3 phosphate molecules.
How is energy released from ATP?
By breaking down the bonds that hold this compound together.
What is used to breakdown ATP?
The enzyme ATP-ase.
What is the role of ATP-ase?
To breakdown ATP into ADP + Pi.
What is ADP?
Adenosine Di-Phosphate, one adenine molecule and two phosphate ions.
What type of reaction is the breakdown of ATP?
An exothermic reaction, because energy is being released.
What is the reaction for the breakdown of ATP?
ATP -> ADP + Pi
What are the three systems used to regenerate ATP?
- The ATP-PC system.
- The aerobic system.
- The lactate anaerobic system.
How quickly is ATP used up in the muscles?
Very quickly, within 2-3 seconds.
What is PC?
Phosphocreatine, a chemical produced naturally by the body and used to regenerate ATP in the first 10 seconds of intense exercise.
Where is PC found?
Phosphocreatine is found in the sarcoplasm of the muscles.
What are the advantages of the ATP-PC system?
- ATP can be regenerated rapidly.
- PC stores are replenished within 3 minutes.
- No fatiguing by-products.
- Can be extended through supplementation of creatine.
What are the disadvantages of the ATP-PC system?
- Limited supply of PC in the body.
- 1 ATP molecule regenerated for 1 molecule of PC.
- Regeneration can only take place in the presence of oxygen.
An exercise like standing long-jump would use energy from ………………………..?
Stored ATP.
How long will the supply of ATP in the muscles last for?
2-3 seconds.
What type of reaction occurs to re-synthesise ATP from ADP and Pi?
An endothermic reaction, it requires energy.
What is the equation for the re-synthesis of ATP.
ADP + Pi + energy -> ATP.
Where is the energy sourced form for the re-synthesis of ATP?
Food fuels.
In the ATP-PC system, how is ATP resynthesised?
Through Phosphocreatine (PC).
What compound is stored in the sarcoplasm of the muscle cells?
Phosphocreatine (PC).
What reaction/s take place for the ATP-PC system to re-synthesise ATP?
PC -> Pi + C + energy, then,
energy + ADP + Pi -> ATP.
What type of reaction occurs in the ATP-PC system?
This is called a coupled reaction as two reactions occur at the same time.
What enzyme facilitates the coupled reactions in the ATP-PC system?
Creatine kinase.
What is the net reaction for the ATP-PC system?
PC + ADP -> ATP + C.
How and where is PC recreated?
PC is recreated in the muscle cells during the recovery process.
What type of reaction is the recovery process to recreate PC?
An endothermic reaction as it requires energy.
For what type of activity is the ATP-PC system used?
High intensity maximal work lasting between 3 and 10 seconds.
Which energy system would be used in a 100 metre sprint?
Dominated by the ATP-PC system.
How can the efficiency of the ATP-PC system be increased?
Through Phosphocreatine supplementation.
Is the ATP-PC system aerobic or anaerobic?
Anaerobic, there is no oxygen needed.
When is peak anaerobic power attained?
Within the first 5-seconds of flat-out exercise.
How long does it take to deplete PC stores?
Between 7 and 9 seconds.
What are the long-term adaptations to an anaerobic training programme?
- Increases in stores of ATP and PC.
- Increased amounts of anaerobic enzymes such as creatine kinase.
- Results in more energy available more rapidly.
At what point is the ATP-PC system exhausted?
Around 12 seconds as both the muscular ATP and the ATP-PC system are exhausted.
The lactate anaerobic system depends on a chemical process, what is this process called?
Glycolysis
What is glycolysis?
Glycolysis is the breakdown of sugar.
How and where is carbohydrate stored?
As glycogen in the liver and muscles.
The breakdown of glycogen provides energy to re-synthesise ATP from ADP. What enzymes catalyse the breakdown of glycogen?
Glycogen phosphorylase (GPP) and phosphofructokinase (PFK).
What do the enzymes GPP and PFK catalyse?
GPP and PFK catalyse the breakdown of glycogen.
In the lactate anaerobic system where does the breakdown of glycogen occur?
In the sarcoplasm of the muscle cell.
What is the end product of the lactate anaerobic system?
Lactic Acid.
Which enzyme catalyses the conversion from pyruvic acid to lactic acid?
Lactate dehydrogenase (LDH).
In the lactate anaerobic system, glucose is broken down, what are the products of glucose when it is broken down?
6 Phosphates (2ATP) and pyruvic acid.
What is the main enzyme responsible for the break down of glucose?
Phosphofructokinase (PFK).
What triggers the break down of glucose?
Low levels of phosphocreatine activate the breakdown of glucose molecules.
What happens to pyruvic acid in the absence of oxygen?
It is converted into lactic acid.
Using the lactate anaerobic system, as work intensity increases lactic acid accumulates, what does this cause?
Lactic acid produces muscle fatigue and pain as the low pH inhibits enzyme and cross bridge formation.
What energy system would be dominant in a 400 metre run?
The lactate anaerobic system.
What energy system would be dominant in a 100 metre swim?
The lactate anaerobic system.
When would the lactate anaerobic system be utilised for exercise?
Duration up to 30 - 60 seconds.
Extra oxygen taken in after exercise removes lactic acid, how does it do this?
Lactic acid is converted into pyruvic acid.
What is the OBLA?
Onset of blood lactate accumulation, the point at which blood lactate becomes extensive enough to suppress performance.
When lactic acid builds too high performance must stop, what is this called?
OBLA (Onset of blood lactate accumulation)
OBLA is dependant on individual fitness, what range does it lie between?
2 and 4 mmol l^-1
What are the three stages involved in the aerobic system?
1) Glycolysis;
2) Kreb’s Cycle (citric acid cycle);
3) Electron Transport Chain.
In which system is OBLA produced?
The lactate anaerobic system.
Where does glycolysis occur?
In the sarcoplasm of the muscle cells.
In both the aerobic and lactate anaerobic systems what is the ATP ratio?
There is 2 ATP molecules per molecule of glucose.
Which stage of the aerobic system occurs in the presence of oxygen?
The Kreb’s cycle and the Electron transport chain.
Where does the Kreb’s cycle occur?
In the matrix (fluid) of the mitochondria.
Where does the electron transport chain occur?
In the cristae of the mitochondria.
What is formed in the Kreb’s cycle?
Citric acid (6 carbons) aswell as H^+,electron pairs, CO2 and 2ATP.
What is used in the Kreb’s cycle?
2 molecules of pyruvic acid combine with oxaloaceticacid and acetyl coA.
What products from the Kreb’s cycle are used in the electron transport chain?
H^+ and electron pairs.
How does the electron transport chain work?
The H^+ and electron pairs have potential energy, this is released in a controlled manner. Oxygen combines with the final H^+ ions to produce water and 32 ATP.
What is beta oxidation?
The metabolism of fats aswell as carbs to produce ATP.
Which system does Beta Oxidation occur in?
The aerobic system.
Explain the steps involved in beta oxidation:
Triglycerides -> Glycerol and fatty acids -> Acetyl CoA -> Kreb’s cycle.
What are the advantages of the lactate anaerobic system?
- ATP can be regenerated quickly due to few chemical reactions needed.
- With Oxygen present, lactic acid is converted back into glycogen.
- Produces an extra burst of energy.
What are the disadvantages of the lactate anaerobic system?
- Lactic acid is a by-product.
- Only releases a small amount of energy from glycogen in anaerobic conditions.
