Aerobic Respiration

Respiration is the process by which living organisms release energy from glucose. Aerobic respiration uses oxygen and is the most efficient form of respiration. This lesson covers the equations, the site of the reaction, and its importance for all living organisms — a key topic in the AQA GCSE Combined Science Trilogy specification (8464).

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What Is Respiration?

Respiration is a chemical reaction that occurs continuously in every living cell. It is not the same as breathing (which is ventilation). Respiration is the process of releasing energy from glucose to power life processes.

All organisms respire — plants, animals, fungi, bacteria and protists. Respiration happens all the time, in every cell, day and night.

Exam Tip: Never confuse "respiration" with "breathing." Breathing is the mechanical process of ventilating the lungs. Respiration is a chemical process in cells.

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Aerobic Respiration

Aerobic respiration is respiration that requires oxygen. It is the main source of energy for most organisms under normal conditions.

Word Equation

$$\text{glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water}$$glucose+oxygen→carbon dioxide+water

Balanced Symbol Equation

$$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O}$$C6​H12​O6​+6O2​→6CO2​+6H2​O