3.3 Break it down!

• Biologie
• Middelbare school
• havo
• Leerjaar 3

3.3 Break it down!

Why should pregnant women eat a lot of protein?

Which of the following is not a function of fat?

1. Protect inner organs
2. Help to absorb vitamins
3. Building block
4. Protect against disease

Which of these food products are high in protein?

1. Salmon
2. Vegetable oil
3. Blueberries
4. Oatmeal

What tips could you give someone who wants to have a healthy diet?

Learning goals

You will know..

• What the four stages of food processing are.
• What enzymes are.
• Why we need enzymes. 

ingestion-digestion-absorption-elimination

Ingestion: placing food in mouth

Digestion: making food particles smaller

              - mechanical/chemical

Absorption: smal particles go into blood

Elimination: get rid of waste products 

digestion

mechanical => chewing

chemical  => breaking food down using enzymes

enzymes 

substrate is broken down

Chemical digeston step 1: 

• the place: the mouth (oesophagus)
• the enzyme: amylase
• the liquid: saliva
• the nutrient: carbohydrates
• the products: glucose & maltose

• The enzymes in your saliva start breaking down the carbohydrate molecules into maltose and glucose.

Chemical digeston step 2: 

• the place: the stomach
• the enzyme: protease
• the liquid: chyme and hydrochloric acid
• the nutrient: proteins
• the products: amino acids

• The enzymes in your chyme start breaking down the protein molecules into amino acids.

Before chemical digeston step 3: 

• the place: liver
• the enzyme: none
• the liquid: bile
• the nutrient: fats

• Bile is an alkalyne and neutralises the acid in the chyme. (drops the pH).
• Bile emulsifies (breaks chemical bonds) fats.

Chemical digeston step 3: part A

• the place: the duodenum
• the enzyme: lipase
• the liquid: chyme and bile
• the nutrient: fats
• the products: fatty acids and glycerol

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Closing

Homework:

Next lesson: 

Learning goals achieved?

- What are the four stages of food processing.

- What are enzymes.

- Why do we need enzymes. 

Ingestion

Mechanical digestion

Chemical digestion

MOVING THE FOOD INTO YOUR MOUTH

BREAKING THE FOOD INTO SMALLER PIECES.

THIS IS DONE BY YOUR TEETH

BREAKING THE FOOD INTO EVEN SMALLER PIECES.

USING ENZYMES TO BREAK DOWN THE FOOD MOLECULES. 

What is the end product matching the enzyme called 'protease'?

1. Amino acids
2. Protein
3. Fatty acids
4. Nutrients

Fases of digestion. Put them in the right order.

1

2

3

4

digestion

ingestion

absorption

egestion

What is the difference between mechanical and chemical digestion?