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Chapter 1  Energy and

Photosynthesis

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Energy

Both living and non-living things need energy.

Energy is needed for things to move and

 work.

Living things need energy to carry out life

processes.

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 Are Tom and Corrine correct?

I don’t need

energy when

I’m resting. 

I don’t need

energy when

I’m thinking. 

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 Where do the followingthings get energy from?

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Food is the source of energy for living

things. Do the following food come from

 plants or animals?

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 Trace the source of the food we eat. Do most of

the food come directly or indirectly from plants?

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I eat only meat, noodles

and bread. I don’t depend

on plants for food too!

Meat-eaters like tigers don’t

depend on plants for food

and energy. 

 Are Tom and Corrine correct?

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Photosynthesis

Plants use light energy, carbon dioxide and water to make food in a process called

 photosynthesis.

 The food produced is in the form of sugar.

Oxygen gas is given out during photosynthesis.

Carbon dioxide + Waterlight

Sugar + Oxygen

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 Where do the carbon dioxide, water and light

needed for photosynthesis come from?

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During photosynthesis, plants trap sunlight

using a green pigment called chlorophyll whichis found in the chloroplasts of plant cells.

 Which parts of plants can you find chlorophyll?

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How does carbon

dioxide enter the

leaves? How dooxygen and water

 vapour escape from

the leaves?

Stomata are tiny openingsusually found on the

underside of leaves.

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Is it true… 

… plants get food from the soil?

… fertilisers are food for plants? 

… plants take in water through the leaves? 

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 Testing for starch

 Yellowish

brown iodine

solution

Starch mixed with iodine

solution

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Put on your

thinking cap… 

 The leaf shown here hasbeen prepared and tested

for starch with iodine

solution. Which part(s)of the leaf has/have

made food?

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Investigating whether carbon dioxide is

necessary for photosynthesis

 What is the difference between the two set-ups?

 What is the purpose of putting solution X in

set-up A?

XSet-up A Set-up B

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Investigating whether light is necessary

for photosynthesis

 Variable to change

 Variables to keep constant

Observations/Measurements to make

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Put on your thinking cap… 

Is a Venus flytrap able to carry out photosynthesis?

 Why does it need to trap insects or other small

animals?

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Is it true… 

… plants cannot make food in artificial light? 

… plants with non-green leaves cannot carry

out photosynthesis?

… only the leaves of plants can carry out

photosynthesis?

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Plants make food in

the form of starch. 

They store

the starch in

their leaves. 

 Are Tom and Corrine correct?

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