Respiration – Aerobic and Anaerobic Respiration

Respiration – Aerobic and Anaerobic Respiration


Cellular respiration can be simplified down into:

glucose + oxygen ? carbon dioxide + water (+ energy)

However, it is a much more complicated process, comprising of about 30 different steps which can be condensed down into three main stages:

  • glycolysis
  • the Krebs Cycle
  • the respiratory chain


Aerobic and Anaerobic Respiration

Respiration can be split up into two main sections: anaerobic and aerobic.

In the anaerobic part, which is the part which requires no oxygen, glucose is broken down into pyruvate. This process is known as glycolysis and takes place in a cell’s cytoplasm. Each molecule of glucose adds up to two ATP molecules.

In the presence of oxygen pyruvate will then go onto the aerobic part. However, if there’s no oxygen then it is converted into lactate, otherwise known as lactic acid. It’s stored like this until oxygen is available when it’s converted back to pyruvate.

The second, aerobic part, which takes place in the mitochondria. It involves the complete oxidation of pyruvate. This forms carbon dioxide and water. A lot more ATP is produced at this stage with each molecule of glucose creating 34 ATP molecules.