8A6 Enzymes
1. What do the enzymes in the washing powder do?
2. Why does it say to wash at 40 oC?
What are enzymes?
• Enzymes are proteins made by cells
• Enzymes are biological catalysts
Denatured enzymes
• When enzymes are denatured they stop working.
• Denatured means that they lose their ability to do
their job properly.
• Enzymes can become denatured when:
- the temperature gets too high (human enzymes
work best at 37 C).
- the surroundings are too acid or alkaline.
Ideal conditions
Digestive enzymes work best at certain pH values.
Amylase prefers alkaline
conditions.
Proteases in the stomach
prefer acid.
Enzymes in the small
intestine prefer alkaline
conditions.
Enzyme investigation
Think about these things before you start the investigation.
• How can you show that amylase is breaking down
starch?
• How will you know when starch has been broken down?
• What variables may affect how quickly the reaction
happens?
• How will you measure and control the variables?
• What quantities of materials will you need?
• What equipment will you need?
• How will you make sure your investigation is safe?
Which food, which enzyme, which product?
Click to reveal the answers.
Food
glucose
lipase
fat
Enzyme
Product
protein
protease
amino acids
fat
lipase
fatty acids
starch
amylase
glucose
protease
amylase
protein
fatty acids
amino acids
starch