In this module, you will learn:

  • what is digestion
  • the role of enzymes in digestion
  • the three types of enzymes

Resources to help you:

  • Textbook: page 70
  • Notebook: page 18

Watch the video

See how the digestive system works

Source: https://www.youtube.com/watch?v=Og5xAdC8EUI

You can change the speed to 0.75x to make it easier to listen.

The different organs involved in digestion (The digestive system)

Credit: @Krisdog via Yayimages

Digestion

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We learnt that there are different food groups and each have their importance for growth as well as for energy. However, the food that we eat are made of large molecules that our body cannot use. The food needs to be digested before it can be used.

Digestion is the process whereby food that we eat is broken down into smaller simpler molecules in order for our body to be able to use it.

In our body, we have special proteins called enzymes that help to speed up the reactions of digestion.


We will be looking into three types of enzymes:

  1. carbohydrase
  2. protease
  3. lipase

The three types of enzymes

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Carbohydrase


  • digest carbohydrates
  • end product is simple sugars


In the mouth, our salivary glands produce saliva which contains amylase (a type of carbohydrase).

Amylase will digest starch (a carbohydrate) into glucose (simple sugar).

Protease


  • digest proteins
  • end product is amino acids



Our stomach produces gastric juices that contains the enzyme protease. It breaks down proteins into amino acids.

Our body uses these amino acids to make new proteins that help our body grow.

Lipase


  • digest fats
  • end product is fatty acids and glycerols

The pancreas produces pancreatic juice that contains all three types of enzymes; pancreatic amylase (a carbohydrase), protease and lipase.

The lipase together with bile produced by the liver, helps to digest fats into fatty acids and glycerols.


The digestion of fats happen in the duodenum, a part of the small intestine.

Time for practice quiz

Now that you have learnt about enzymes, you can click below to do a practice quiz.

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