Energy Systems in the Human Body

by trandonbtinternetcom (student)

AS and A Level Physical Education (Sport & Coaching)

Energy Systems

ATP is broken down by the enzyme ATPase to form ADP and Pi. Energy is release exothermically from this reaction. ATP can be used in the body for up to 3 seconds of muscular work at high intensity. The bond that holds the phosphate to the ATP molecule has potential energy, which when broken released energy.

ATP/PC System takes place in the sarcoplasm. PC is broken down by the enzyme creatine kinase to produce a phosphate, creating and energy. The phosphate from this reaction can be used to resynthesize ATP, by reacting ADP + P + energy. This is an endothermic reaction. Overall, there is a yield of 1:1, so there has been a 0 net gain of ATP. This process can take place anaerobically, so therefore, no oxygen is required in this system. This process can only supply energy to resynthesize ATP between 8 - 10 seconds. Athletes such as Usain Bolt and best suited to this system, as their main events only last up 10 seconds, so therefore, the athlete can carrying on using this system for whole race, instead of using another system, which can take up more time and cause lactic acid.

Password

Confirm Password

I agree to the terms of service and privacy policy

After this stage is the lactic acid system, which also takes place in the sarcoplasm. Glucose is first broken down into pyruvic acid by the enzyme PFKase, releasing 2 molecules of ATP. In the absence of oxygen, the pyruvic acid if further broken down into lactic acid by the enzyme LDHase. Lactic acid is a fatiguing product, so therefore, pH levels will decrease, and enzymes will denature and no longer work as biological catalysts. This process can resynthesize ATP between 10 seconds and 3 minutes at high intensity. This is an anaerobic process, so no oxygen is required. A ...

This is a preview of the whole essay

The last system is the aerobic system which is split up into 3 stages. The first stage is the glycolysis stage, which takes place in the sarcoplasm. In the presence of oxygen, pyruvic acid (from the lactic acid system) is diverted to the aerobic system. Pyruvic acid combines with coenzyme A to form Acetyl coenzyme A. This is also known as the link reaction. Acetyl coenzyme enters the matrix of the mitochondria which combines with the 4 carbon molecule oxaloacetic, to form the 6 carbon molecule citric acid. This is further broken down to a 5 carbon molecule. During this process, carbon dioxide is released via the lungs, 2 molecules of ATP are produced, electron carriers NAD and FAD are released, and hydrogen atoms are also removed via oxidation.

The final stage of the aerobic system is the electron transport chain. This takes place in the cristae of the mitochondria. The electron carriers and the hydrogen atoms from the Krebs cycle enter the cristae of the mitochondria. They combine to form NADH and FADH, and are carried down the electron transport chain, where hydrogen splits up into H+ and e- ions. The hydrogen electrons pass down the electron transport chain, which provides energy to resynthesize 34 molecules of ATP. The hydrogen ions (H+) combine with oxygen to form a water molecule. This is released due to sweating, breathing or urine. Overall, in the aerobic system a total yield of 1:38 has been produced of ATP. This process can resynthesize ATP between 3 minutes and 1 hour. This system works aerobically.