Energy Systems Flashcards
What is ATP?
An organic chemical that provides energy in living cells
What is the ATP-PC system?
An anaerobic process and rethink synthesises ATP when the enzyme creating kinase detects high levels of ADP
What is phosphocreatine?
An energy rich phosphate compound found in the sarcoplasm of the muscles
What is a coupled reaction?
When energy required by one process is supplied by another process
What are mitochondria?
The working organelles that keep the cells full of energy
What is the lactate anaerobic system?
A system that produces high powered energy for high intensity of effort in events such as 400 meters
What is aerobic respiration?
The usual process for releasing energy for your muscles
What is anaerobic respiration?
When your muscles have to work at a very intense level, anaerobic respiration takes place
Sporting examples of anaerobic respiration?
Sprinting and weightlifting
Sporting examples of aerobic respiration?
Long distance running,
Sporting examples using both anaerobic and aerobic respiration?
Rugby, boxing, cycling
What is the energy currency in the body?
ATP
What are the three energy systems?
- Aerobic system
- ATP-PC system
- Anaerobic glycolytic system
What type of system is the ATP-PC system?
Anaerobic, does not require oxygen to produce energy
What is the ATP-PC system used for?
Needed for high intensity, short duration events e.g. shot putt, sprinting
How long does the ATP-PC system last?
10 seconds for high intensity, short duration events (PC stores run down quickly)
What is the predominant energy system in high intensity, short duration events lasting between 5 and 8 seconds ?
ATP-PC
What energy is used for activities lasting less than 3 seconds?
Energy just from the breakdown of ATP
Advantages of the ATP-PC system?
- ATP can be re-synthesised rapidly
- Phosphocreatine stores can be re-synthesised quickly
- No fatiguing by-products
- Possible to extend the time the ATP-PC system is utilised through creatine supplementation
Disadvantages of the ATP-PC system?
- Only a limited supply of phosphocreatine in a muscle cell
- Only one mole of ATP can be re-synthesised for every mole of PC
- PC re-synthesis can only take place in the presence of oxygen
What is the lactic acid system?
Anaerobic glycolytic system
What is the lactic acid system used for?
Short term energy system - used for high intensity exercise over a long period of time (60-90 seconds) - 400m
What type of process is the lactic acid system?
Aerobic, does not require oxygen
How does the lactic acid system get energy?
Uses carbohydrates from food eaten and converts them into glucose
Where is excess energy stored from the lactic acid system?
Liver and muscles as glycogen (easily accessible)
When does the lactic acid system kick in?
- When the ATP-PC system fades after 10 seconds
- Activated by low levels of phosphocreatine
- Glycogen stored in liver and muscles is broken down into glucose
- This produces energy to covert ADP back to ATP
- Glucose produces 2 molecules of ATP
- Glucose converted to pyruvic acid by phosofructokinase but with no oxygen present, lactic acid is produced as a by product
- Lactic acid if allowed to accumulate diffuses into the tissue fluid and blood
- If not removed quickly builds up to impede muscle contractions and causes fatigue
What is glycolysis?
The process in which glucose is converted into pyruvate to produce energy
What is the Krebs Cycle?
A series of cyclical chemical reactions that take place in the mitochondria
What is the electron transport chain?
A series of chemical reactions that take place in the cristae of the mitochondria
What is Beta-Oxidation?
The breakdown of fatty acids in order to provide ATP
What is the energy continuum?
The sequence which covers the type of respiration required during exercise
What three stages are in the aerobic system?
- Glycolysis
- The Krebs Cycle (citric acid cycle)
- The electron transport chain
How many ATP are produced in the aerobic energy production?
38 ATP
What type of activity is the aerobic energy system used for?
Long, continuous and moderate exercise
What is aerobic metabolism?
Break down of foods to energy
What is the first stage of the aerobic energy system?
- Glycolysis occurs at the presence of oxygen
- Lactic acid not produced
- Pyruvic acid converted into acetyl-CoA
What is the second stage of the aerobic system?
- Once pyruvic acid diffuses into mitochondria, Krebs Cycle occurs
- Reactions produce 2 molecules of ATP and carbon dioxide
- Hydrogen is taken to the electron transport chain
What is the third stage in the aerobic system?
- Hydrogen is carried to the electron transport chain by hydrogen carriers
- This occurs in the cristae of the mitochondria
- Hydrogen splits into hydrogen ions and electrons and charged with potential energy
- Hydrogen ions are oxidised into water, while providing energy to resynthesise ATP
- 34 ATP molecules formed
How does Beta-oxidisation occur?
- Fats used as an energy source in the aerobic system
- Krebs Cycle and electron transport chain can metabolise fat and carbohydrates to produce ATP
Advantages of the aerobic system?
- 36 ATP produced
- No fatiguing by-products
- Lots of glycogen and triglyceride stores so exercise can last for a long time
Disadvantages of the aerobic system?
- Complex system, takes a while for enough oxygen to become available to meet the demands of the activity and ensure glycogen and fatty acids are completely broken down
- Fatty acid transportation to muscles is low, requires 15% more oxygen to become broken down
What is the lactate threshold?
The point during exercise at which lactic acid quickly accumulates in the blood
What is OBLA?
The point when lactate levels go above 4 millimoles per litre
What is buffering?
A process which aids the removal of lactate and maintains acidity levels in the blood and muscles
What is oxygen consumption?
The amount of oxygen we used to produce ATP
What is VO2 Max?
Maximum volume of oxygen that can be taken up by muscles per minute
What is sub maximal oxygen deficit?
When there is not enough oxygen available at the start of exercise to provide all the energy (ATP) aerobically
What is EPOC?
The amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time
What is fast component?
The restoration of ATP and phosphocreatine stores and the re-saturation of myoglobin with oxygen
