ATP/PC System

• ATP stands for adenosine triphosphate
• it is a chemical energy
• exists in all cells in the body
• it is the only immediate usable source of energy in the body
• this means we have a permanent  supply
• ATP is potential energy so it is stored and ready to use when required

ATP is made up of:

• one complex element, ADENOSINE
• three simple PHOSPHATE elements

...these are held together by bonds. When the bond is broken, energy is released. ATPase breaks this bond.

• the body only has enough ATP to supply energy for 2-3 seconds of muscular work

• ATP must be rebuilt as quickly as it is used

• the resynthesis of ATP is an endothermic reaction because it requires energy

• coupled reactions supply energy to resynthesise ADP into ATP

ATP/PC system > provides energy > from coupled reactions > to resynthesise ATP

• PC (phosphocreatine) also stores potential energy

When ATP levels fall, the enzyme creatine kinase is released which breaks down the PC bond.

This releases energy and is an exothermic reaction.

The energy released from the PC is used to resynthesise ADP into ATP in an endothermic reaction.

• does not require oxygen > anaerobic system
• takes place in the muscle sarcoplasm
• limited stores of ATP
• one PC resynthesises one ATP
• energy for resynthesis can only be provided for 3 to 10 seconds during all out sprinting
• controlling enzyme > creatine kinase
• no fatiguing by products