Use of nutrients - Respiration

Glucose is released from the liver into the circulation system to maintain a steady concentration in the blood. The glucose travels to the capillaries in the organs and tissues where it is absorbed by cells and used in respiration.

Aerobic respiration

Aerobic respiration involves oxygen and transfers the energy in glucose into a chemical called ATP. Cells use energy (ATP) for a range of life processes including transporting materials, cell division, and making new cell parts. A lot of energy is formed by aerobic respiration.

Anaerobic respiration

Sometimes low concentrations of oxygen occur inside the mammals body eg muscles working quickly  or for a long time. When oxygen is low anaerobic respiration occurs.

During anaerobic respiration glucose is changed into lactic acid and small amounts of energy (ATP)

Less energy is produced than aerobic respiration as glucose is only partially broken down. Lactic acid made is poisonous, causing cramps and stops mucles working. Oxygen is needed to break lactic acid and is called oxygen debt. Supplying oxygen to remove lactic acid is why high breathing and pulse rates continue after exercise.

Cellular respiration makes other life processes possible because the energy produced can be used for those life processes. eg for growth, the energy can be used to join chemicals together to make the larger molecules for growth. Energy can also be used for the other life processes (MRS GREN)