Photosynthesis is the process by which plants make food using light energy.

Theory behind the hook

This hook makes links to students’ prior knowledge by using an everyday example of solar powered items in everyday life and the manner in which they utilise light energy. In this way students will be able to relate to the topic being introduced.

How this hook works

This hook serves to build on prior knowledge and uses a selection of images and questions to stimulate and engage students. It uses analogies from everyday life to show that light is a source of energy and can be converted into other energy forms. The clip begins with the statement that we need food for energy and questions how plants source their food. Solar powered items (calculator, security cameras and solar panels to heat water) are displayed and their energy source is questioned. At this point the clip can be paused to allow for feedback on the energy source for these items. Their energy source is the sun. A plant is compared to a solar panel in that it uses light energy from the sun to produce food, an energy conversion. Finally it is explained that the process of using light energy to produce food in plants is known as photosynthesis.

Questions & Answers

  • Photosynthesis is an example of an energy conversion. What energy conversion takes place?
    Photosynthesis involves the conversion of light energy to chemical energy.
  • Why do you think that leaves wither from autumn onwards?
    Shorter days and less sunlight.

Cross Curricular Links

Links can be made to Junior Certificate Geography and different climates and the implications for photosynthesis.


Calculate the number of leaves lost on trees over time (in autumn lose more as less sunlight).