Respiration teaching resources

Worksheets and lesson ideas to challenge students aged 11 to 16 to think hard about respiration, anaerobic respiration and fermentation (GCSE and Key Stage 3)
Respiration teacher brief

Overview: respiration is a cellular process that happens continuously inside all living organisms. In eukaryotic cells, aerobic respiration takes place in mitochondria (anaerobic in the cytoplasm). During respiration, the energy stored inside glucose is transferred, allowing work to be done inside the cell. Because respiration can’t be seen, it is helpful for students to make comparisons to the analogous process of combustion. Spend some time making sure that students understand how the reactants of respiration i.e. glucose and oxygen arrive at a cell in the foot, for example, and how the products escape. Then consider what the energy is used for inside the cell i.e. for muscle contraction, protein synthesis, active transport or maintaining a constant internal body temperature. When there is insufficient oxygen, the oxidation of glucose is incomplete and so lactic acid in animals (3C compound) or ethanol and carbon dioxide in plants (2C + 1C) is produced alongside some energy being transferred.

Big idea: organisms require a supply of energy and materials for which they often depend on, or compete with, other organisms

Key concept: respiration is an exothermic reaction which is continuously occurring inside living cells. The energy transferred when glucose reacts with oxygen supplies all the energy needed for living processes. When respiration stops, cells die.

Linked knowledge: cells, energy, chemical equations

Misconception [scientific idea]: gas exchange and respiration are the same [respiration is a cellular process involving a chemical change, gas exchange simply involves the movement of gases from one place to another]; plants don’t respire or respire only at night [plants respire all the time]; inhaled air stays in the lungs or head [inhaled oxygen is transported to the cells via the circulatory system].

Teaching resources

Where to start?

Ask students what would happen to a worm if it was placed inside a sealed jar with plenty of food and water. Try to illicit the idea it would die because it would run out of oxygen. Then probe deeper. Would it come back to life if we gave it oxygen? What is the oxygen used for?

Comparing combustion with respiration

The screaming jelly baby is a great demonstration to use when teaching respiration. You have a fuel, oxygen and a huge amount of energy being transferred. What are the similarities and differences of this reaction compared to cellular respiration?

GCSE activity and worksheet comparing respiration with combustion. Students use a simple Venn diagram to consider the similarities and differences between combustion and respiration. This open-style activity is an excellent platform to challenge students and assess their understanding of this fundamental process. (PDF)

Breathing and respiration are not the same

GCSE activity on respiration and breathing. Do plants get a temperature when they are sick? This activity looks at research that shows infected leaves have higher temperatures than healthy leaves. Students use this research to think about the process of respiration and consider how it differs from breathing. By looking at respiration in plants first, many misconceptions linking breathing to respiration can be avoided. (PDF)

How much energy is in food?

How much energy is transferred when we burn food? Follow this link to a scientific investigation that asks students to determine the amount of energy present in Quavers and rice cakes. The practical can be used to help students make the link between respiration and combustion.

Experiencing anaerobic respiration

Ask students to hold one arm above their head and then open and close the attached hand quickly. Repeat this process until the muscles in the arm start to burn. Ask students what is happening and relate the position of the hand to oxygen availability. You can then introduce the concept of anaerobic respiration and lactic acid.

Anaerobic respiration and fermentation

GCSE worksheet on anaerobic respiration and fermentation. Students work in groups of four to silently review what they already know about anaerobic respiration and fermentation in yeast. They then answer a longer answer question comparing and contrasting these two important cellular processes. (PDF)

Going deeper

  • Why don’t you get wine with an alcohol content of above 15%?
  • What evidence suggests that mitochondria were once free-living bacteria?
  • Aerobic respiration is exothermic. What are the endothermic reactions that can happen because of respiration?
  • What is brown fat and why do new born babies have quite a lot of it?
  1. Biological molecules
  2. Food tests
  3. Enzymes
  4. Photosynthesis
  5. Respiration