Stages of Respiration (Edexcel A Level Biology (A) SNAB): Revision Note

Stages of Respiration

• Glucose is broken down in stages, each of which consists of a series of chemical reactions

• These chemical reactions are controlled by intracellular enzymes that catalyses reactions within the cell

• This ensures that the energy trapped within the chemical bonds of the glucose molecule is released gradually and not all at once

• A sudden release of such a large amount of energy would result in an increase in body temperature to levels that would denature enzymes

• Each stage of aerobic respiration occurs at a particular location in a eukaryotic cell:

  • Glycolysis takes place in the cell cytoplasm

  • The Link reaction takes place in the matrix of the mitochondria

  • The Krebs cycle takes place in the matrix of the mitochondria

  • Oxidative phosphorylation occurs at the inner membrane of the mitochondria

Four Stages of Respiration Table