The Creatine Kinase


Creatine kinase is an enzyme that ensures that the cells have sufficient energy available through a biochemical reaction. It is found in the muscle cells and in the brain and is always released by the body when the muscle tissue is damaged due to illness or stress. This can be the case during sports activities or during childbirth without any disease value. However, the creatine kinase level is also an important indicator for life-threatening diseases such as heart attack.

What is creatine kinase?

The creatine kinase or also creactine kinase (CK) is an important enzyme in the human body, which is needed for the energy metabolism. Creatine kinase is mainly found inside the muscle cells – but the enzyme is also found in the brain and other organs, for example the heart. Depending on the organ, creatine kinase has a different chemical structure, so that four sub-forms can be distinguished:

  • CK-MM is found in the muscle cells of the locomotor system
  • CK-MB in the heart muscle cells
  • CK-BB in the nerve cells of the brain and
  • CK-Mini in the sheaths of the mitochondria.

What is the function of creatine kinase?

Creatine kinase belongs to the group of kinases. This group of enzymes has the task of providing the cells with sufficient energy for movement and metabolism. This is because the cell needs energy in the form of adenosine triphosphate (ATP) for every muscle contraction.

This molecule consists of carbon, hydrogen, oxygen and three phosphate atoms. In order to release energy, the compound must be broken down and a phosphate atom split off. What remains is a low-energy adenosine diphosphate (=compound with two phosphates).

Since the storage of ATP in the cells is very low at 5 micromoles per gram of muscle, ATP is quickly consumed. In order for energy to continue to be available, ATP must be restored. This is done as quickly as possible with the help of creatine kinase.

Creatine kinase is released as soon as there is a lack of energy due to illness or stress and the associated loss of muscle cell tissue. It passes into the blood and attaches a new phosphorus group to the adenosine phosphate without oxygen consumption, so that the adenosine phosphate is converted back into the activated state ATP. This topic may also be of interest to you:

  • The role of enzymes in the human body
  • The effect of creatine