Photosynthesis

• Biology
• 4th Grade

Photosynthesis

What is Photosynthesis?

Photosynthesis is the process by which plants make their own food.

The word photosynthesis can be separated to make two smaller words:

“photo” which means light

“synthesis” which means putting together

What is needed for Photosynthesis?

To make food, plants need not just one but all of the following:

• carbon dioxide
  
• water
• sunlight

Let’s take a look at how these are collected by plants.

1. Carbon dioxide from the air passes through small pores (holes)in the leaves. These pores are called stomata.
2. Water is absorbed by the roots and passes through vessels in the stem on its way to the leaves.
3. Sunlight is absorbed by a green chemical in the leaves.

What happens during Photosynthesis?

The photosynthesis process takes place in the leaves of plants. The leaves are made up of very small cells. Inside these cells are tiny structures called chloroplasts. Each chloroplast contains a green chemical called chlorophyll which gives leaves their green color.

What happens during Photosynthesis?

1. Chlorophyll absorbs the sun’s energy.
2. It is this energy that is used to split water molecules into hydrogen and oxygen.
3. Oxygen is released from the leaves into the atmosphere.
4. Hydrogen and carbon dioxide are used to form glucose or food for plants.

What have you learned so far?

Plants need carbon dioxide, water and sunlight to make their food. 

The food they make is called glucose. In addition to glucose, plants also produce oxygen. This information can be written in a word equation as shown in the next slide.

What is the source of energy for photosynthesis?

1. Gravity
2. Electricity
3. Magnetism
4. Sunlight

Which gas is used by plants during photosynthesis?

1. carbon dioxide
2. oxygen
3. nitrogen
4. phosphorus

Green plants use carbon dioxide in photosynthesis.

1. True
2. False

Fact or Opinion?
Leaves change color because of photosynthesis.

1. fact
2. opinion

References

https://photosynthesiseducation.com/photosynthesis-for-kids/