Biotechnology in action
Yeast: biofuel and bread
- Yeast carries out anaerobic respiration, making ethanol and carbon dioxide.
- the ethanol can be used as a biofuel,
- in bread-making, the carbon dioxide makes the dough rise.
Practice
Yeast respiring anaerobically produces:
Anaerobic respiration in yeast makes ethanol (a biofuel) and carbon dioxide (which makes bread rise).
Enzymes in industry
- pectinase breaks down cell walls to release more (and clearer) fruit juice.
- biological washing powders contain enzymes (proteases, lipases) that digest stains, even at lower temperatures.
- (Supplement) lactase breaks down lactose to make lactose-free milk.
Practice
Pectinase is used to:
Pectinase breaks down cell walls so more clear juice is released from fruit.
Practice
Biological washing powders contain enzymes that digest stains, even at lower temperatures.
Proteases and lipases in biological washing powders break down stains, working at lower temperatures.
You've got it
Key idea
- yeast (anaerobic respiration) → ethanol (biofuel) + carbon dioxide (makes bread rise)
- pectinase → more fruit juice; proteases/lipases in washing powders digest stains
- (Supplement) lactase → lactose-free milk