3.1.7 Biotechnology 2 Flashcards
What is biotechnology?
When microorganisms are used to produce useful products.
Name 3 foods or drinks that use biotechnology in their production
Cheese Yoghurt Bread Beer Wine
Which ingredients are needed to make cheese?
Milk
Bacteria
Rennet
Describe the cheese-making process.
- Add milk and bacteria to a container
- Add the enzyme ‘rennet’ to the mixture to curdle the milk.
- Milk separates into ‘curds’ and ‘whey’.
- Press the curds to make a solid cheese.
- Leave cheese to mature.
What does the bacteria do when it is added to the milk?
It converts lactose (milk sugar) into lactic acid via fermentation.
What is the equation for fermentation by bacteria when added to lactose?
Lactose –> Lactic Acid + Energy
Why is the lactic acid produced by bacteria in cheese making so useful?
It gives the cheese a tangy flavour.
Why does rennet need to be added to milk in the cheese making process?
Rennet is an enzyme that helps to curdle the milk into curds and whey.
What is ‘curds’?
The solid that separates from milk when it curdles in cheese production.
What is ‘whey’?
The liquid that separates from milk when it curdles in cheese production.
What are the ingredients needed to make yoghurt?
Milk
Bacteria (usually from another yoghurt)
Describe the yoghurt-making process
- Heat milk in a large container (pasteurisation)
- Add bacteria to milk.
- Keep the mixture warm for several hours.
- Lactic acid curdles the milk into yoghurt.
What is pasteurisation?
When milk is heated to kill unwanted bacteria,
What do bacteria do to the milk during yoghurt production?
They convert lactose sugar in the milk into lactic acid.
What does lactic acid do in yoghurt production?
Helps to curdle the yoghurt
Adds a tangy flavour
Prevents harmful bacteria growing in the yoghurt.
