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
Estimate the optimum temperature for yogurt production.
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Answer
The optimum temperature for yogurt production is estimated to be around 42 ± 1 °C based on the graph.
Step 2
Describe how microorganisms change milk into yogurt.
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Answer
Microorganisms, specifically bacteria, play a key role in the fermentation process. They convert lactose, the sugar present in milk, into lactic acid. This process lowers the pH of the milk, which causes the proteins to coagulate, resulting in the thickening and setting of yogurt.
Step 3
Describe the advantages of using microorganisms to produce food.
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Answer
Using microorganisms for food production has several advantages. They can accelerate fermentation processes, enhance flavors, and can be cultivated at lower costs compared to traditional methods. Additionally, microorganism-based processes often result in improved nutritional value and preservation.
Step 4
Complete the sentence regarding preventing contamination.
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Answer
The correct option is D: using aseptic precautions.
Step 5
Complete the sentence regarding the enzyme produced by genetically modified yeast.
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Answer
The correct option is A: chymosin.
Step 6
Describe the advantages of making cheese using the enzyme produced by genetically modified yeast.
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Answer
The use of chymosin from genetically modified yeast in cheese production offers advantages such as consistency in enzyme activity, reducing production time, and potentially lowering production costs. Additionally, it can enhance cheese quality by ensuring a uniform texture and flavor.