Photo AI
The graph shows the effect of temperature on the time taken to make yogurt - Edexcel - GCSE Biology - Question 4 - 2013 - Paper 1
Question 4
The graph shows the effect of temperature on the time taken to make yogurt. (i) Use the graph to estimate the optimum temperature for yogurt production. (ii) Descr... show full transcript
Worked Solution & Example Answer:The graph shows the effect of temperature on the time taken to make yogurt - Edexcel - GCSE Biology - Question 4 - 2013 - Paper 1
Step 1
Step 2
Describe how microorganisms change milk into yogurt.
Answer
Microorganisms, such as bacteria, play a crucial role in yogurt production by:
- Bacteria: Different strains of bacteria are introduced to the milk.
- Changing lactose: These bacteria metabolize lactose, which is the sugar in milk.
- Converting lactose into lactic acid: The lactose is fermented into lactic acid.
- Lowering the pH: As lactic acid accumulates, it lowers the pH of the milk.
- Coagulating proteins: The lowered pH causes the proteins in the milk to coagulate, thickening the mixture into yogurt.
Step 3
Step 4
Describe the advantages of using microorganisms to produce food.
Answer
Using microorganisms to produce food offers several advantages:
- Efficiency: Microorganisms can grow rapidly, leading to quicker food production.
- Nutritional value: Certain microorganisms can enhance the nutritional content of food, making it richer in essential nutrients.
- Flavor and texture: They contribute unique flavors and textures, making food more appealing.
- Biopreservation: Some microorganisms can inhibit the growth of spoilage organisms, increasing food shelf life.
Step 5
Step 6
Describe the advantages of making cheese using the enzyme produced by genetically modified yeast.
Answer
The use of genetically modified yeast to produce enzymes for cheese making has notable advantages:
- Consistency: The enzyme production can be controlled to ensure consistent quality and yields.
- Efficiency: Genetically modified yeast can produce enzymes in larger quantities compared to traditional sources.
- Sustainability: Using yeast may reduce the need for animal-derived rennet, making cheese production more sustainable.