HOW DO MUSCLES GET THE ENERGY TO WORK?
In muscles, it is essential that Calcium is present, as this gives the muscles the ability to contract and relax. For muscles to contract energy is needed: the energy can only be provided by the breakdown of a chemical called adenosine triphosphate (ATP). As ATP is broken down, a phosphate molecule is broken off, reducing the phosphate molecules, from 3 to 2. This produces adenosine triphosphate. However for the muscles contraction to continue, the ATP has to rebuild from ADP and p (ADP+P+= ATP). As this occurs, more energy is released and so more energy is available. Therefore, when the muscles is used for an extended time the ATP supplies are lowered. This is the most important anaerobic fuel source accessible.The equation for ATP(energy) is ATP-> energy+ adenosine diphosphate(ADP+P). there are two pathways anerboic and aerobic respiration. aerobic requires oxygen in order for respiration to take place. The equation for this is glucose + oxygen -> carbon dioxide + water(+energy). Anerboic respiration does not require oxygen it only happens when there is not enough oxygen for aerobic respiration. The equation for this is glucose -> lactic acid (+energy relesed). When a muscle contracts it creates movement which is called an isotonic contraction. An isotonic contraction can normally concentric where the muscle shortens as the fibres contract. Muscle fibres use ATP for contraction but only for a few seconds, as when the fibres contract the muscle lengthens leaving the muscle to contract with no follow-on movement. The fastest way to regenerate ATP (energy) is by the breaking down of creatine phosphate to provide creatine and an additional phosphate energy to convert ADP back to ATP. This benefits contracting muscles because ATP is therefore available very quickly. This can only happen for a short period of time the creatine phosphate stored in the muscle is used quickly, especially during high intensity workouts. Although many athletes take creatine supplements it adapts this into creatine phosphate in the muscles. Taking supplements exploits the levels of creatine phosphate stored in the muscles, therefore the amount of energy stored is maximised. Another method where ATP can be produced in the muscle cell can be through glucose and glycogen. This can occur during physical activities, The body needs an energy source. The energy source is a molecule called glucose. The cells of the body breaks down glucose through a process called glycolysis. Glycolysis energy is transferred from bonds in the glucose molecule to phosphate bonds in ATP and GTP. What normally happens is glucose is broken down in to glycolysis to form ATP, NADH + H+ and 2 molecules of pyruvate. Glucose is converted to pyruvate after their conversion to one of the sugar intermediates in this glycolytic pathway. The last method where ATP can be produced is in the muscle cell from fatty acids this can be broken down into various tissues which produce energy. This gives a high yield of ATP throughout fatty acid oxidation & oxidative phosphorylation. They are preferentially used by some tissues as a most important energy source. Heart muscle derives 60% of its energy from long-chain fatty acid oxidation And skeletal muscle uses them at mutually rest but during extended aerobic muscle exercise.
WHAT IS MUSCLE FATIGUE AND WHAT CAUSES IT:
Muscle fatigue is when people work out and feels a sensation that their muscles are tired, aching or exhausted it gets to the point that they are working out so hard that they feel as they cannot move the muscles anymore. When this happens, the muscle that is artificial will not be able to function as it did at the beginning of a workout. Although the muscles do develop microscopic tears that must be repaired in order for the muscle to grow in strength and size. Muscle fatigue does stop the muscles from contracting normally as a result of lactic acid...
Please join StudyMode to read the full document