Understanding the Roles of Digestion
Secondary | Health | Views: 738
- The food we eat contains lots of nutrients which our body needs so we can stay fit and healthy.
- When we eat food, our digestive system helps to break food down into smaller pieces.
- Once the food is broken down into small enough pieces our body can then absorb all of the nutrients to keep us healthy.
- This practical helps to show us how food is broken down and nutrients are absorbed as it moves through our body.
Note: This is very messy, so be prepared to have a lot of cleaning up!
You Will Need:
- A selection of your favourite foods such as beans and biscuits (the sloppier the better).
- Two large bowls: one labelled Mouth and the other labelled Small Intestine.
- A pair of tights with one leg cut out: labelled as the Large Intestine.
- Two buckets or bowls: one labelled Blood and the other labelled Toilet.
- A potato masher: labelled as the Teeth.
- Two sandwich bags: one labelled Stomach and the other labelled Rectum.
- A pair of scissors.
- A big sponge: labelled as the Villi.
- Four containers such as fruit squash bottles, cola bottles or measuring jugs: one labelled Saliva, one labelled Enzymes, one labelled Acid and finally one labelled Bile.
What to Do:
- Firstly, make up your four solutions of Saliva, Enzymes, Acid and Bile. Saliva: Add water. Enzymes: Add water, washing up liquid and red food colouring. Acid: Add water and a little bit of malt or white vinegar. Bile: Add water and a few granules of gravy powder.
- Collect your favourite foods and add them to the bowl labelled Mouth and using the Teeth, mash the food up into small pieces.
- Add the Saliva and some of the Enzymes to help break down the food then using your hands break down the food even further. Your hands represent your Tongue.
- Once the food is broken down pour it into the bag labelled Stomach.
- Add the Acid and some more of the Enzymes to further break down the food.
- Using the scissors cut a hole in the corner of the Stomach bag and let the contents pour into the bowl labelled Small Intestine.
- Add more Enzymes and the Bile to the Small Intestine and mix them together.
- Using the Villi soak up some of the liquid and transfer this to the Blood.
- Transfer the rest of the contents of the Small Intestine into the Large Intestine.
- Squeeze the water out of the Large Intestine and transfer the remaining solid to the Rectum.
- Transfer the contents from the Rectum to the Toilet.
- The Enzymes and Saliva in the Mouth help to break down the Starch.
- The Acid and Enzymes in the Stomach start the digestion of Protein.
- The Bile added to the Small Intestine is produced in the Liver and this breaks down Fats.
- Enzymes in the Small Intestine break down Starch, Proteins and Fats.
- The Sponge acts like the Villi and absorbs nutrients, which then get transferred to the Blood.