Page 8 - 新思维科学学生用书9 样章

1.1 Photosynthesis

How plants make food

Plants make food by photosynthesis. ‘Photo’ means ‘light’. ‘Synthesis’ means ‘making’. So
photosynthesis means ‘making with light’.

Activity 1.1.1

Words beginning with photo
Work in a team.
In two minutes, write down as many words as you can think of that start with ‘photo’.
The winning team is the one which has thought of the most words – but only if they are

all real words, and are spelt correctly.
What does each word have to do with light?

In photosynthesis, plants use:
• water, which they get from the soil energy from
• carbon dioxide, which they get from the air light

• energy, which they get from sunlight.

The energy in sunlight is captured by a green pigment, called carbon
chlorophyll, which is inside some of the cells in the leaves of dioxide
plants.

The plants use the energy to make the water and carbon
dioxide combine together in a chemical reaction.

Two new substances are made in the reaction. These are

glucose and oxygen. water

You can write the word equation for photosynthesis like this:
water + carbon dioxide → glucose + oxygen

Photosynthesis happens in the leaves of a plant. You will find
out more about this in the next topic.

Questions
1 What are the reactants in photosynthesis?
2 What are the products in photosynthesis?

7