Photosynthesis

Home learning focus

Learn about the reactants in, and products of, photosynthesis.

This lesson includes:

  • two videos to help you understand photosynthesis and how you can measure it
  • two practise activities to help reinforce learning

Learn

Watch this short film to learn more about photosynthesis:

Science presenter Jon Chase explains photosynthesis

Photosynthesis

  • Photosynthesis is a chemical reaction that takes place inside a plant, producing food for the plant to survive.

  • Carbon dioxide, water and light are all needed for photosynthesis to take place.

  • Photosynthesis happens in the leaves of a plant.

The process of photosynthesis

Plants need food to respire, grow and reproduce. Unlike animals, plants are able to make their own food by the process of photosynthesis.

Photosynthesis takes place in the part of the plant cell containing chloroplasts, these are small structures that contain chlorophyll.

For photosynthesis to take place, plants need to take in carbon dioxide (from the air), water (from the ground) and light (usually from the sun).

In this video , we learn how knowledge of photosynthesis is used to maintain a football pitch.

The head groundsman at Derby County FC discusses how he uses knowledge of photosynthesis to maintain the pitch.

Here is the word equation for photosynthesis:

Here is the chemical equation for photosynthesis:

Carbon dioxide enters through the stomata on the underside of the leaf.

Water is absorbed by the root hair cells and is transported to the leaf by the xylem vessels.

Sunlight provides the energy needed for photosynthesis to take place. In this process carbon dioxide and water are converted into oxygen (a waste product that is released back into the air) and glucose (the source of energy for the plant).

Oxygen is released through the stomata on the underside of the leaf; glucose is transported around the plant in the phloem vessels.

How are leaves adapted for photosynthesis?

  • They are green because they contain lots of chlorophyll to absorb sunlight.

  • They have a large surface area to maximise the amount of sunlight they can absorb.

  • They are thin, allowing easy diffusion of gases into and out of the leaf.

  • They have veins (xylem and phloem) to allow the transport of water, mineral ions and glucose (food).

To facilitate photosynthesis, leaves have chlorophyll, a large surface area, are thin and have veins.

Practise

There are lots of fun ways to practise what you know about photosynthesis.

Activity 1

Find out how much you know about photosynthesis in this quick quiz!

Activity 2

Try measuring photosynthesis for yourself:

A short video showing you how to measure photosynthesis.

Have a go

A student in a dark room, with a single light shining on a beaker filled with water and a plant, writing observations.

WHAT YOU NEED: A dark room with a desk lamp, some pondweed, a glass of water, a ruler and a paper and pen.

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There's more to learn

Have a look at these other resources around the BBC and the web.

KS3 Biology
11-14 Biology
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