ScienceLO: to describe ways in which nutrients and water are

transported within animals, including humans.

To describe ways in which nutrients and water are transported within animals, including humans.

What do you think will happen to the skittles if I pour 100ml of water in the middle of this plate?

Make a prediction!

Did you predict that the food colouringwould start to run?

Why does this happen?

Skittles are coated in food colouring and sugar. When you pour

water over the skittles, the coloured coating dissolves, spreading

through the water.

The colour and sugar dissolve into the water and then diffuse

through the water, making it the colour of the skittle.

Diffusion is where particles move from an area where there are

lots of particles, to an area where there are not so many particles.

There were lots of coloured particles on the skittles, but when

water was added, the coloured particles diffused through the

water, where there weren’t so many coloured particles. This

resulted in the water changing colour.

Do you remember learning about diffusion in the human body?

• The skittles in this experiment were supposed to represent food. The food colouring was supposed to represent nutrients found in food.

• How do you think this experiment relates to the movement of nutrients within our our bodies?

• Write down your answer. Try to include the words ‘absorption’ and ‘blood’.

https://www.bbc.co.uk/bitesize/topics/zv9qhyc/articles/zdkfvk7

Watch this BBC Bitesize clip on what happens in your intestines?

Once broken down, the

nutrients are absorbed through

the walls of our intestines into

the blood in a process called

diffusion (like in the Skittles

experiment).

What do you think will happen if I pour 100ml of water on top of this gummy worm and leave it over

night?

Make a prediction!

The purple gummy worm was soaked in water over night and the yellow gummy worm is straight out of the packet.

Did you predict that the gummy worm would get bigger?

Why does this happen?

Water moves from an area where there are fewer particles to an

area where there are more particles. Because there are lots of

particles in the jelly worm, water diffuses into the jelly worm, making it larger.

A similar process happens in our body. Water doesn’t need

breaking down and moves between membranes in the body to arrive

in the correct place, again via our blood through a diffusion.

process called osmosis .

Osmosis only applies to water (or a solution) and is dependent on a

semi-permeable membrane.

The water in the snake experiment represents the water in our

bodies

What else they think is transported around the body using the process of diffusion?

of particles

of particles

What else they think is transported around the body using the process of diffusion?

of particles

of particles

Water, nutrients, oxygen, carbon dioxide, toxins, hormones, etc.

We know that the blood transports oxygen, nutrients, water and certain

chemicals around the body, but what do we get rid of?

Think back to this clip to help you.

We know that the blood transports oxygen, nutrients, water and certain

chemicals around the body, but what do we get rid of?

Carbon dioxide out through the lungs and waste expelled through urine and faeces.

The process of diffusion removes these unwanted things from cells and they ultimately become urine and faeces once processed through the kidneys and colon.

During diffusion, particles move from an area of high concentration (where there are lots of particles) to an area of low concentration (where there are not so many

particles).

Copy these images down and draw an arrow showing the direction where the particles are most likely to move.

I have done the first one for you.

Here there are lots of particles (a high concentration), but on the other side there are no particles (a low concentration).

During diffusion, particles move from an area of high concentration (where there are lots of particles) to an area of low concentration (where there are not so many

particles).

Copy these images down and draw an arrow showing the direction where the particles are most likely to move.

ANSWERS

Because in this last box the particles are evenly spread, they do not need to move.

Create your own drawing showing diffusion. Below are a few examples

that can help you.