An overview of respiration

• Respiration involves the transfer of?chemical potential energy?from nutrient molecules (such as carbohydrates, fats and proteins) into a usable energy form (through the synthesis of ATP) that can be used for work within an organism
• It is a vital process that takes place in the cells of all living organisms
• There are two forms of respiration depending on the oxygen availability of the cell:
  • Aerobic?respiration
  • Anaerobic?respiration
• Aerobic?respiration is the process of breaking down a?respiratory substrate?in order to produce ATP?using oxygen
• Anaerobic?respiration takes place in the absence of oxygen?and also breaks down a respiratory substrate but produces?less ATP?for the cell
• The main?respiratory substrate?involved in respiration is?glucose

Aerobic respiration

• Aerobic respiration can be summarised by the following equation
  • Glucose + oxygen → ?carbon dioxide + water + energy

The stages of aerobic respiration

• The process of aerobic respiration using glucose can be split into four stages
• Each stage occurs at a particular location in a eukaryotic cell:
  • Glycolysis?takes place in the 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?which involves the?electron transport chain?and?chemiosmosis?and occurs at the inner membrane of the mitochondria

Overview of the four stages of aerobic respiration

Four Stages of Respiration Table