Energy Systems Flashcards
(6 cards)
ROLE OF ATP
ATP- Adenosine triphosphate is the chemical form of energy that our body uses for all muscle contractions.
ATP is made up of one molecule of adenosine and three molecules of phosphate.
Without ATP we would have no energy for movement. A small store of ATP is found in muscle cells so that it is available instantly and is immediately accessible form of energy for exercise. ATP stores in the muscle last for approximately two to three seconds so the body needs to find a way to resynthesise ATP when used up they form ADP. ADP is re synthesised from creatine phosphate bonds which release phosphate binds with ADP to form ATP. ADP means adenosine di-phosphate. Di means two.
ATP-PC SYSTEM
АТР-РС- ATP is the chemical form of energy that our body uses for all muscle contractions. There is sufficient ATP in the muscles for approximately 2-3 seconds of work; after this more ATP needs resynthesising (rebuilding). In the ATP-PC system the energy required to resynthesise ATP is provided by phosphocreatine (PC).
PC is made up of a molecule of phosphate and a molecule of creatine. There is enough PC in the muscle cell to continue to resynthesise ATP for approximately 8-10 seconds of physical work.
Advantages / disadvantages
The advantages of this system are that energy is released quickly and no waste products are formed. The disadvantages are the limited stores of PC and the 2-3 minutes required to fully recover these stores. This means there is insufficient recovery time during play in many sporting situations to recover the PC stores once they have been used.
Recovery time- Once the supply of PC has been broken down to resynthesise ATP, energy is needed from another energy system to resynthesise the PC stores.
This energy is provided from the aerobic system.
LACTATE SYSTEM
The lactate system of energy production is anaerobic. This means that oxygen is not used in the process. This system produces energy relatively quickly, so it is good for short-duration, high-intensity activities.
The food fuel source carbohydrate is broken down by the body to form glucose. Some of this glucose goes into the blood stream, some is converted to glycogen and stored in the muscle cells and liver.
Anaerobic glycolysis- Glucose and glycogen are partially broken down by the lactate system to produce ATP. ATP is used in this breakdown, but more ATP is produced than used, each molecule of glucose produces two net (additional) molecules of ATP.
Energy can be supplied by the lactate system for approximately 1-2 minutes of intense activity.
Recovery- The lactate produced through this system will accumulate unless there is oxygen available to break it down. As the lactate accumulates it changes the acidity of the blood, reducing the efficiency of muscle contraction, causing muscle fatigue. Therefore, this system can only be used maximally for 1-2 minutes before requiring recovery. A recovery time of approximately 8 minutes will aid the removal of lactate from the muscles and also give time to replace the glycogen stores in the muscles.
AEROBIC SYSTEM
The aerobic system- Stored fats and carbohydrates are used as the fuel source for this energy system. They are broken down into glycogen, glucose and fatty acids.
Glycolysis then pyruvate is broken down later in the process rather than forming lactate. Two net ATP molecules are produced. Krebs cycle takes place in the mitochondria. The pyruvate from anaerobic glycolysis forms Acetyl-CoA, which is broken down, using oxygen to form carbon dioxide and hydrogen. Two ATP molecules are released. Hydrogen from Krebs cycle combines with oxygen to form H20 as a waste product, and 34 molecules of ATP are produced.
The advantage of this is that it yields large numbers of ATP molecules compared to either of the anaerobic energy systems. The disadvantage of this system is that releasing the larger quantities of energy involves more chemical reactions making the system slower, and unsuitable for anaerobic activity as it cannot produce the required amount of energy quickly enough for intense activity.
Recovery time- The time required for recovery of this system can be a few hours or as long as 2-3 days, depending on the intensity and duration of the exercise and your level of fitness.
LONG TERM EFFECTS (ADAPTIONS)
Aerobic system adaptations
There are three main adaptations: increased ability to use fats as a food fuel source, increased storage of glycogen and increased number of mitochondria.
FACTORS AFFECTING ENERGY SYSTEMS
Diabetes is caused by the body’s inability to regulate the amount of glucose in the blood. Type 1 diabetes- This occurs when the body is not able to produce insulin. As the body cannot get energy from glucose it looks to break down fat and protein. Type 2 diabetes- This is the more common form of diabetes. It develops when not enough insulin is produced by the body, or when insulin is present but is not carrying out its function.
Hypoglycaemic attack
This is when blood sugar falls too low. People with diabetes must monitor glucose levels before and after activity and may need to eat carbohydrates before exercise, during or after to help balance their blood glucose.
The lactate system in children This energy system is still developing during childhood, and is not fully developed until around 20 years. This is due to: lack of muscle mass, lower glycogen stores and fewer essential enzymes required for energy production.
