Flashcards
Chapter 1- Energy Systems
Flashcards do conjunto (19)
- 1ATPAdenosine triphosphate
Energy is released by breaking the bonds that hold ATP together.
ATPase is the enzyme that breaks down ATP into ADP+Pi. - 2Sources of energy to replenish ATPPhosphocreatine- Found in the sarcoplasm of muscle cells. It is used to re-synthesise ATP in the first 10 seconds of intense exercise. Easy to break down and is store within the muscles. However, its stores are limited.
Carbohydrates-Stored as glycogen in the muscles and liver. Converted to glucose during exercise. Preferred source of energy for high-intensity exercise.
Fats-Stored as triglycerides and converted to free fatty acids when required. Fat produces more energy per gram than glycogen. The pre-dominant source of energy during low-intensity exercise.
Protein-Converted to amino acids. Only used when stores of glycogen are low. - 3Energy systemsThe ATP-PC system
The lactic acid system
The aerobic system - 4The ATP-PC systemHigh-intensity activities lasting less than 10 seconds.
Anaerobic.
Phosphocreatine is stored in the muscles and broken down to creatine and phosphate using the enzyme creatine kinase.( The energy released is used for the re-synthesis of ATP)
Aerobic energy is needed for this system to recover. - 5Advantages and Disadvantages of the ATP-PC systemAdvantages:
-Energy released quickly.
-ATP resynthesised quickly.
-No by-products formed.
Disadvantages:
-Limited supply of phosphocreatine.
-Full recovery takes up 2-3 minutes. - 6The lactic acid systemHigh-intensity activities lasting approx. 1 min.
Anaerobic.
Glycolysis breaks glycogen down into glucose. The enzyme phosphofructokinase breaks glucose down into pyruvic acid. In the absence of oxygen, the pyruvic acid is converted to lactic acid and 2 molecules of ATP are produced. - 7Advantages and Disadvantages of the lactic acid systemAdvantages:
-ATP can be re-synthesises quickly.
-In the presence of oxygen, lactic acid can be converted into glycogen.
Disadvantages:
-Lactic acid is the by-product. - 8The aerobic systemLow-intensity activities lasting longer than 1 minute.
Aerobic.
ATP is regenerated from glucose and fats in 3 stages:
Glycolysis-Glycogen is broken down into glucose which is then broken in pyruvic acid.
Krebs Cycle-The pyruvic acid diffuses into the matrix of the mitochondria and a complex cycle of reaction occur. The reactions result in the production of 2 ATP molecules + Carbon dioxide + Hydrogen.
Electron transport chain-The hydrogen from the Krebs cycle is carried into the chain. This occurs in the cristae of the mitochondria. Water is formed + 34 ATP molecules. - 9Advantages and Disadvantages of the aerobic systemAdvantages:
-Lots of ATP molecules.
-No fatiguing by-products produced.
-Large stores of glycogen and triglyceride.
Disadvantages:
-Complicated system.
-Takes a long time for oxygen to become available.
-Fatty acid transportation to muscles is low and require more oxygen to be broken down. - 10Stages and function of the Krebs CyclePyruvic combines with acetly coenzyme A.
Beta oxidation occurs as fatty acids combine with acetly coenzyme A.
This forms oxaloacetic acid.
Oxaloacetic acid combines with coenzyme A.
Forms citric acid.
Oxidation of citric acid/ hydrogen ions removed from citric acid.
Production of carbon dioxide.
Hydrogen ions/H+ passed onto the electron transport chain.
Resynthesis of 2 ATP. - 11The lactate thresholdThe point at which lactic acid rapidly accumulates in the blood.
It occurs when lactate is produced faster than it can be removed. - 12The energy continuumThis refers to the continual movement from one energy system to another depending on the intensity and duration of the exercise.
- 13Causes of fatigue-Glycogen depletion
-Lactic acid built-up
-Reduced rate of ATP synthesis
-Dehydration
-Reduced levels of calcium
-Reduced levels of acetylcholine
-Thermoregulation - 14The recovery process:EPOCExcess post-exercise oxygen consumption(EPOC)- Oxygen is transported to the working muscles to maintain elevated rates of aerobic respiration.
-The fast replenishment stage (alactacid component) - Resaturation of myoglobin with oxygen, resynthesis of ATP and resynthesis of PC.
-The slow replenishment stage (lactacid component) - Removal of lactic acid by converting it to a protein (urea), water&CO2, Glycogen and Glucose. - 15V02 MaxThe maximum volume of oxygen that can be taken in and used by the muscles per minute.
Average person- Work at around 50-60% V02 max.
Trained performer- Work at around 85-90% of V02 max. - 16Factors affecting V02 MaxGender:
-Females have a lower maximum cardiac output, a lower blood volume + a lower tidal volume.
Age:
-Older individuals have a a lower maximum heart rate, higher blood pressure + Increase in residual volume.
Lifestyle:
-Smoking, sedentary lifestyle and poor diet can all reduce V02 max values.
Training:
-Training can increase maximum cardiac output, reduce body fat + increase stroke volume.
Body composition:
-V02 max decreases as percentage body fat increases. - 17Onset of blood accumulation(OBLA)The point at which lactate starts to rapidly accumulate in the blood.
OBLA occurs when the concentration of lactic acid is around 4mmol-1.
It gives an indication of endurance capacity.
It is expressed as a percentage of V02 max. - 18Factors that affect the rate of lactate accumulationOBLA- The point at which lactate starts to accumulate in the blood. It starts at 4mmol/litre and occurs as the body is unable to provide enough oxygen to break down lactate.
The intensity of the exercise- Higher the intensity, the faster OBLA occurs.
Fitness of the performer- Physiological adaptive responses due to training, e.g. More mitochondria, greater capillary density & Improved gaseous exchange.
V02 max of the performer- Higher the level the more delayed OBLA.
Respiratory exchange ratio- Closer the value to 1.00 quicker OBLA occurs.
Type of muscle fibre- Slow twitch muscle fibres reduce OBLA. - 19How is lactic acid removed from the body?The lactacid component (Slow component) of EPOC
Uses oxygen
Lactic acid is converted to:
-Carbon dioxide and water
-Glycogen and stored in the liver
-A protein
-Some excreted in sweat and urine
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- AS - Level PE (Applied Physiology) FlashCards sobre Chapter 1- Energy Systems , criado por Ellie Shuter em 28-09-2016.
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- Ellie Shuter
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