Respiration

The Big Idea

The big idea is: all organisms require energy to live. During respiration, food (usually in the form of glucose) reacts with oxygen producing carbon dioxide and water. When this happens, energy is transferred from the food which is then used to carry out all the organism’s life processes.


To make the most of this idea you should focus children’s attention on why they require energy and provide them with a range of life processes to demonstrate this.

This should include examples from:

  1. animals, such as moving, keeping warm [in mammals and birds], growing, maintaining the body and reproducing (eg making eggs) and

  2. plants, such as growing, and making seeds.

You can use muscles as an example to help children to make links between the effect of exercise on breathing and heart rate and relate this to the muscle’s extra demand for food and oxygen to fulfil its energy requirements.

The key problem with respiration is that it is an abstract concept that occurs in individual cells.

Progression

KS2

Children are likely to have only been introduced to organs. Cells (which organs are made from) and respiration are not explicitly taught until Key Stage 3 but are unifying concepts for processes such as breathing, blood circulation and feeding.

KS3

  • Aerobic and anaerobic respiration in living organisms, including the breakdown of organic molecules to enable all the other chemical processes necessary for life.

  • A word summary for aerobic respiration

  • The process of anaerobic respiration in humans and micro-organisms, including fermentation, and a word summary for anaerobic respiration.

  • The differences between aerobic and anaerobic respiration in terms of the reactants and the products formed and the implications for the organism.