Energy Systems (P1) Flashcards
What does ATP stand for and what is the definition?
Adenosine triphosphate is the only usable form of energy in the body.
How is ATP used to for energy?
The enzyme ATPase is used to break down ATP leaving ADP and an inorganic phosphate. This process releases energy.
What three energy systems help to convert fuel into energy?
- ATP-PC System
- Anaerobic Glycolytic System
- The Aerobic System
What two fuels fuel chemical reaction to resynthesise ATP?
Food and phosphocreatine (PC)
What is phosphocreatine?
An energy rich phosphate found in the sarcoplasm of the muscles
What fuel is used by the ATP-PC system?
PC
How does ATP-PC work to provide energy?
The system resythesises ATP when the enzyme creatine kinase detects high levels of ADP. It breaks down PC in the muscles to phosphate and creatine which releases energy. The energy is then used to convert ADP to ATP in a coupled reaction.
What is a coupled reaction?
When energy required by one process is supplied by another process.
What are the advantages of the ATP-PC system?
.ATP can be re-synthesised quickly
.PC stores can be replenished quickly- 50%-30s, 100%-3 minutes
.no fatiguing by-products
. length of the system can be increased by creatine supplementation
What are the disadvantages of the ATP-PC system?
.limited supply of PC (5-8 seconds worth)
. 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 does the duration of the anaerobic glycolytic system depend on?
The fitness of the individual and the intensity of the activity.
What fuel is used and broken down in the anaerobic glycolytic system and where does it come from?
Glucose- supplied form the digestion of carbohydrates and stored in muscles and liver as glycogen.
How does the anaerobic glycolytic system work to provide energy?
.enzyme glycogen phosphorylase breaks down glycogen to glucose
. enzyme phosphofructokinase breaks the glucose to pyruvic acid
. enzyme lactate dehydrogenase breaks down pyruvic acid into lactic acid
Through this process energy is released meaning two molecules of ATP is re-synthesised for one molecule of glucose broken down
What is the name of the process that occurs in the anaerobic glycolytic energy system?
Anaerobic glycolysis and takes place in the sarcoplasm of the muscle cell
What are the advantages of the anaerobic glycolytic system?
. quick re-synthesis of ATP and lasts longer than ATP-PC system
. presence of oxygen can allow lactic acid to be converted back into liver glycogen or used converted into co2 and h2o and used as a fuel
. used for sprint finish
What are the disadvantages of the anaerobic glycolytic system?
. lactic acid as a by-product
. small amount of energy released from glycogen under anaerobic conditions
When is the aerobic system the preferred energy system?
When exercise intensity is low and oxygen supply is high
What two sources of energy can the aerobic system break down for energy?
Glucose and fat
What are the three stages of the aerobic system?
1) Glycolysis/Beta oxidation
2) Krebs cycle
3) Electron transport chain
What is glycolysis in the aerobic system?
A process by which glucose is converted to pyruvate acid to produce two molecules of ATP for every molecule of glucose undergoing glycolysis. Takes place in the sarcoplasm of the muscle cell
How does the pyruvic acid from glycolysis enter the krebs cycle?
oxidised into two acetyl groups and carried by the coenzyme A
What is beta oxidation?
Stored fat is broken down into glycerol and free fatty acids. The fatty acids undergo beta oxidation where they are converted to acetyl coenzyme A in order to enter the krebs cycle. More ATP can be produced than glycolysis.
What is the krebs cycle?
The acetyle groups combine with oxaloacetic acid forming citric acid which undergoes oxidative carboxylation which gives off hydrogen and carbon. The carbon forms co2 and is breathed out and hydrogen is taken to the electron transport chain. 2 ATP is produced.
What is the electron transport chain?
Involves a series of chemical reactions in the cristae of the mitochondria where hydrogen splits into ions and electrons. The ions are oxidised to form water and the electrons provide the energy to re synthesise ATP. 34 ATP are produced.
What are the advantages of the aerobic system?
.More ATP produced- 36
. no fatiguing by products
. lots of glycogen and triglyceride stores so exercise can last for a long time
What are the disadvantages of the aerobic system?
. complicated system so can’t be used straight away
What is the energy continuum?
A term which describes the type of respiration used by physical activities. The energy system used depends on the activities duration, intensity, fitness of the individual, presence or lack of oxygen
What is the duration of activities for each energy system?
<10 =ATP-PC
8-90 secs= ATP-PC and anaerobic glycolytic
3+ mins= aerobic
What is the ATP generation of the slow twitch fibres?
. Mainly aerobic system
. produces max ATP
. production is slow but fatigue is unlikely
What is the ATP generation of the fast twitch fibres?
Mainly anaerobic systems
. ATP production is not efficient
. ATP production is fast but doesnt last as long as the muscle fibres are less resistant to fatigue
What is oxygen consumption?
The amount of oxygen we use to produce ATP
What is VO2 max?
The maximum volume of oxygen that can be taken up by the muscles per minute.