Lesson video

Hello everyone, how are you today?

Hope you're feeling really good.

My name is Ms. Afzal and I'll be your teacher for this lesson.

I'm feeling pleased about that because we've got a pretty interesting topic ahead.

We're looking at photosynthesis.

Maybe you already know a little bit about photosynthesis.

Hopefully you'll learn a lot more by the end of this lesson.

The lesson comes from the unit of work, Plant nutrition and photosynthesis.

So if you're ready to dive into this interesting subject, if you have some focus, energy and enthusiasm, we'll begin our lesson now.

The outcome for today's lesson is I can identify the reactants and products of photosynthesis and write a word summary of the process.

I hope that sounds interesting to you.

We have some keywords in our lesson.

I'd like us to go through them one at a time saying them out loud.

My turn, your turn.

Producer, chemical reaction, photosynthesis, carbon dioxide, glucose.

Good to hear those keywords out loud.

And now I'd like you to share with someone nearby.

Have you heard of any of these keywords?

Do you have any idea what these keywords mean?

Pause here and share.

Thanks for sharing.

Let's find out what these keywords mean.

A producer is an organism that makes its own food.

In a chemical reaction, substances are broken down and react to form new substances.

Photosynthesis is a series of chemical reactions by which producers make their own food.

Carbon dioxide is a compound made of carbon and oxygen that is a gas at room temperature and a reactant in photosynthesis.

Glucose is a sugar, carbohydrate, produced by photosynthesis.

So these are our keywords, producer, chemical reaction, photosynthesis, carbon dioxide, and glucose.

Let's look out for them.

Let's listen out for them.

Let's think carefully about these keywords.

They'll be coming up in our lesson today.

Our lesson is called photosynthesis and it has two learning cycles.

How producers make their own food, and the reactants and products of photosynthesis.

Let's begin by exploring how producers make their own food.

Plants and other producers make their own food.

The food is made by a process called photosynthesis.

This process happens in the leaves and other parts of the plant that are above the ground.

Here can see a leaf of a maple tree, such a beautiful shape.

Photosynthesis can only happen when there is light.

Now let's take a look at this word photosynthesis.

If we break it down, photo means light and synthesis means to make.

So put this together and this gives us our word photosynthesis.

What other words do you know that contain photo?

Pause here and share with someone.

Thanks for sharing any words that you know containing photo, which means light.

Let's have a check for understanding, true or false.

Photosynthesis happens in plant roots.

Pause here while you decide.

Is this statement true or false?

Well done if you selected false.

Now, I'd like you to justify your answer by choosing from one of these two statements.

A, photosynthesis happens in plant leaves when there is light, or B, photosynthesis happens in all parts of a plant.

Pause here while you decide which of these statements justify your earlier answer.

Well done if you selected statement A.

Indeed photosynthesis happens in plant leaves when there is light.

This statement justifies your earlier answer.

Leaves are made up of cells.

Photosynthesis takes place inside the cells.

So we have that beautiful leaf of a maple tree and here we can see on the right the leaf cells seen through a microscope.

Pause here and share with someone any details you notice in this image of the leaf cells.

Thanks for sharing what you noticed.

As you look carefully at these leaf cells.

Let's have a check for understanding.

Match the one correct start of the sentence to the one correct end of the sentence to make one single sentence.

So the options for the start of the sentence are, plant food is made between plant cells.

Plant food is made from plant cells.

Plant food is made inside plant cells.

And here are the options for a correct ending for the sentence.

By the process of cellular respiration.

By the process of photosynthesis.

By the process of digestion.

So pause here while you match the one correct start of the sentence to the one correct end of the sentence to make one single sentence.

Well done if you matched the correct start of a sentence, plant food is made inside plant cells to the correct ending by the process of photosynthesis.

Photosynthesis needs light.

And here we can see the light being absorbed by leaves.

Light transfers energy from the light source to the leaf cells.

This provides the energy needed for photosynthesis to take place.

Let's have us check for understanding.

Which statement about light and photosynthesis is true?

Choose from this selection.

A, light creates cells for photosynthesis.

B, light is made by photosynthesis.

C, light provides the energy for photosynthesis.

Pause here while you decide which of these statements about light and photosynthesis is true.

Well done if you selected statement C.

Indeed light provides the energy for photosynthesis.

This statement about light and photosynthesis is true.

And now it's time for your first task.

Izzy has had a houseplant for a long time.

It is still very small.

She keeps it in a dim corner of the room far away from the window.

There we can see Izzy's tiny houseplant.

Izzy decides to move the plant so that it is next to the window.

Explain how this will help the plant to grow bigger.

So pause here while you have a go at this task of explaining why Izzy's moving the houseplant next to the window will help the plant to grow bigger.

Enjoy your task and I'll see you when you're finished.

It's good to be back with you.

How did you get on with that task of explaining why putting the houseplant next to the window will help the plant to grow bigger?

Perhaps you said something like this.

It will get more light from the sun.

Light transfers energy from the sun to the plant's leaf cells.

This provides energy for photosynthesis.

Photosynthesis makes the plant's food.

This food is used as a source of materials for growth, a source of energy for other life processes.

Well done if you gave an explanation containing some of these ideas.

And now we're onto our next learning cycle, the reactants and products of photosynthesis.

Photosynthesis is a series of chemical reactions that happen inside leaf cells.

And here we can see some leaf cells through a microscope.

During chemical reactions, one or more substances are broken down.

These are the reactants, and one or more new substances are made, these are the products.

Like any chemical process, photosynthesis has reactants and products.

So reactants, substances which are broken down are carbon dioxide gas and water, and products, new substances which are made are glucose and oxygen gas.

So here are the reactants and the products of photosynthesis.

And of course we need the light for this whole process of photosynthesis to take place.

Photosynthesis is not just one chemical reaction.

It's a series of chemical reactions that happen inside plant cells.

But it's useful to remember a word summary of the reactants and products.

So water and carbon dioxide, reactants, give us glucose and oxygen, the products.

Let's go through that one more time.

So water and carbon dioxide are the reactants and they give plants glucose and oxygen, the products.

Let's have a check for understanding.

Complete the word summary for photosynthesis.

So when we have two things as our reactants, they will give us which two products.

Pause here while you complete the word summary for photosynthesis.

Well done if you completed the word summary for photosynthesis in this way.

The reactants are carbon dioxide and water, give the plant the products of glucose and oxygen.

Well done if you completed the word summary for photosynthesis in this way.

So here's our word summary again.

Water plus carbon dioxide give the plant glucose and oxygen.

One of the reactants of photosynthesis is water.

Plants take in water for photosynthesis through their roots.

The water is transported to the leaves for photosynthesis.

As the arrows show us in this image.

Let's take a look at our word summary for photosynthesis once again.

The reactants of water and carbon dioxide give plants the products of glucose and oxygen.

One of the reactants of photosynthesis is carbon dioxide.

Plants in carbon dioxide gas for photosynthesis from the air through their leaves.

And our word summary again.

The reactants of water and carbon dioxide give a plant the products of glucose and oxygen.

One of the products of photosynthesis is glucose.

Glucose is made inside leaf cells.

Glucose is a type of sugar which is a carbohydrate.

It is the plant's food.

The glucose is transported to all plants of the plant, where it is used as a source of energy and as a source of materials to make new cells and tissues for growth.

And we can see the arrows on this image showing us how glucose is transported to all parts of the plant.

One more time.

Our word summary for photosynthesis.

The reactants of water and carbon dioxide give the plant the products of glucose and oxygen.

One of the products of photosynthesis is oxygen.

Plants release this oxygen into the air from their leaves and oxygen is something that we breathe in.

So there's this wonderful relationship that we have with plants where they take in the carbon dioxide that we release and we take in oxygen that they release.

Let's have a check for understanding.

Match each substance to its role in photosynthesis.

So here are our substances, carbon dioxide, glucose, oxygen and water.

And the role made by photosynthesis, used by photosynthesis, made by photosynthesis, used by photosynthesis.

Pause here while you match each substance to its role in photosynthesis.

Well done if you matched carbon dioxide to used for photosynthesis, glucose is made by photosynthesis.

Oxygen is made by photosynthesis and water is used for photosynthesis.

Well done if you matched the substances to their roles in photosynthesis in this way.

Let's have another check for understanding.

Match each substance to the correct description.

Here are our substances, carbon dioxide, glucose, oxygen and water.

And the descriptions, reactant, product, reactant, product.

Pause here while you match each substance to the correct description.

Carbon dioxide is a reactant.

Glucose is a product, oxygen is a product, and water is a reactant.

Well done if you matched the substances to their descriptions in this way.

Let's remember word summary for photosynthesis.

The reactants of water and carbon dioxide give plants the products of glucose and oxygen.

Photosynthesis needs light and we can see in the image the light reaching the plant and the light is being absorbed by the leaves.

However, light is not a substance.

Light is not a chemical reactant in photosynthesis.

Light is not turned into a product during photosynthesis.

Light provides the energy needed for the chemical reactions of photosynthesis to take place.

Glucose is a type of sugar.

A bag of sugar from the shop has a mass of one kilogram.

How many bags or kilograms of sugar do you think a large tree can make in one sunny day?

Pause here and share with someone.

What do you think?

Thanks for sharing.

A large tree can produce around 90 kilograms of glucose from photosynthesis in one day.

Most of the mass of that glucose is made up of carbon atoms.

All of those carbon atoms come from carbon dioxide gas from the air.

Let's have a check for understanding.

Complete the sentences about photosynthesis.

The reactants of photosynthesis are, from the air and from the soil.

Photosynthesis makes a type of carbohydrate called that the plant uses to grow bigger.

Most of the mass of this carbohydrate is made up of, atoms, which were taken in from the air.

So pause here while you complete the sentences about photosynthesis.

Did you complete the sentences in this way?

The reactants of photosynthesis are carbon dioxide from the air and water from the soil.

Photosynthesis makes a type of carbohydrate called glucose that the plant uses to grow bigger.

Most of the mass of this carbohydrate is made up of carbon atoms, which were taken in from the air.

Well done if you completed the sentences about photosynthesis in this way.

And now it's time for our next task.

Lucas buys a small plant in a pot, keeps the plant in a sunny spot.

He waters the plant whenever the soil is dry.

After four months, the plant is much bigger.

What I would like you to do is one, write down what the plant has taken in to enable it to grow.

And two, after four months and two, after four months, the mass of the plant had increased, but the mass of the soil was the same as it was at the start.

Explain why.

So pause here while you have a go at this task.

I'll see you when you're finished.

So how did you get on with that task?

First of all, writing down what the plant has taken in to enable it to grow.

Perhaps you wrote something like this.

The plant took in water from the soil and carbon dioxide from the air for photosynthesis.

The plant also took in light to provide energy for photosynthesis.

And two, after four months, the mass of the plant had increased, but the mass of the soil was the same as it was at the start.

Did you explain why in this way?

The mass of the plant increased because it used carbohydrate from photosynthesis to make new cells and tissues.

Most of the mass of this carbohydrate came from carbon dioxide from the air.

The plant took in water from the soil, but this water was replaced so the mass of soil didn't decrease.

Well done for having a go at this task.

In our lesson, photosynthesis, we've covered the following.

Producers make their own food using a process called photosynthesis.

Photosynthesis can only happen when there is light.

Photosynthesis is a series of chemical reactions that take place inside plant cells.

The reactants of photosynthesis are water and carbon dioxide.

The products are oxygen and glucose, a carbohydrate.

A word summary of the reactants and products of photosynthesis is water plus carbon dioxide gives glucose and oxygen.

Well done everyone for taking part in this lesson.

It was great to explore this incredible process of photosynthesis, this amazing series of chemical reactions that take place inside plant cells and that give us the oxygen that we breathe in, gives us life.

I really enjoyed teaching you, and I hope you enjoyed this lesson too.

I look forward to seeing you at another lesson soon.

Until then, stay curious.