Download - Y7 Life 10 digestive enzymes
Digestive Enzymes
Learning Objective:
• Explain the role of enzymes in digestion.
Starter:
• Name the organs of the digestive system in order.
Can you remember the names of all the parts of the digestive system?
Mouth
Oesophagus
Stomach
Small Intestine
Large Intestine
Rectum
Enzymes
Different enzymes are added by the digestive system at various stages.
There are different enzymes for different functions.
Let’s look at the different enzymes which breakdown food
How do enzymes work?
AmylaseAmylaseAmylaseAmylase
Amyase
Carbohydrates are chains of identical sugar molecules.
The digestive enzymes called carbohydrases break the chemical bonds between the individual sugar molecules in each carbohydrate chain.
carbohydrase
long carbohydrate
moleculesugar
molecules
Enzymes and carbohydrate digestion
Investigation
1. Tie one end of visking tubing, fill with starch & amylase solution.
2. Soak in warm water for 15-20 minutes.
3. Test the water for glucose using Benedict’s solution.
Practical Activity
Safety First: Wear safety
goggles Stand up Tuck your chair &
bags under your desk
Tie back long hair
ProteaseProteaseProteaseProtease
Proteins are made up of amino acids. There are 20 different types of amino acids.
Proteins are digested by digestive enzymes called proteases. These enzymes work in an acidic environment to break proteins into smaller amino acids.
protease
long protein molecule
amino acid molecules
Enzymes and protein digestion
LipaseLipaseLipaseLipase
Fats are digested in two stages:
Firstly, bile (released by the gall bladder) allows the fat to “mix” with water by breaking the fat into smaller droplets. This is called emulsification.
Secondly, the digestive enzyme lipase breaks each fat molecule into the smaller glycerol fatty acid molecules .
bile
lipase +
fat molecule glycerol fatty acids
Enzymes and fat digestion
Digestive EnzymesDigestive EnzymesDigestive EnzymesDigestive Enzymes
Digestive Enzymes
Blue Benedict’s solution turns orangey-red when it is boiled with glucose.
blue turns orange/red= glucose
heat
chopped up food
hot water
Digestive enzymes activity
Digestive Enzymes
Learning Objective:
• Explain the role of enzymes in digestion.