The Creatine Phosphate System

You have already learned that during strenuous activity muscle cells break down ATP, releasing ADP, phosphate and energy. ATP ADP + Pi + Energy

Creatine phosphate in muscle cells breaks down to provide phosphate and energy to convert ADP back to ATP. In your group discuss why this benefits contracting muscle.

Answer… This can help to maximise muscle contraction by making ATP available very quickly. This can only happen for a short period of time. It will stop once the creatine phosphate stored in the muscle has been used up.

Where does the creatine phosphate come from? When demand for energy is low the ATP produced by respiration is used as a source of phosphate and energy to produce creatine phosphate. This acts as an energy store in the muscles.

Summary Copy and complete the diagram below: ATP Creatine Creatine phosphate Phosphate and energy are being transferred between molecules. This is a very fast way of producing ATP for a short period of time.

Creatine supplements Many athletes take creatine supplements. Why do you think they do this? What sort of sports would this be an advantage in?

Answer… When athletes take creatine in supplements it is converted into creatine phosphate in the muscles. Taking supplements maximises the levels of creatine phosphate stored in the muscles, therefore the amount of energy stored is also maximised. Creatine is not banned by major sporting bodies. It may be of most use in activities where short bursts of energy are required. Can you think of any?

Assessment Your task is to write an article on creatine supplements for a sporting magazine. Your article should include: a description of what creatine phosphate is used for by the body a description of the role of creatine supplements the type of activities that may benefit from creatine supplements any other information you think is relevant.

Remember… Most importantly your article should be easy to follow and make sense. Do not copy and paste text – put any research you do into your own words. The people reading a sporting magazine may not be scientists. They have to be able to understand the article.