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5.2. Effects of temperature and pH
A subsection of Biology, 5090, through 5. Enzymes
Listing 10 of 35 questions
Some laundry detergents used to wash clothes contain enzymes. These enzymes break down the molecules that cause stains. Suggest enzymes that may be components of a laundry detergent that will break down stains made of: starch fat. Savinase is a protease enzyme produced by genetically engineered bacteria. The enzyme is a component of laundry detergents. The graphs show the results of an investigation into the effects of temperature and pH on the rate of Savinase activity. rate of Savinase activity 10 20 30 40 50 temperature / °C 60 70 80 90 rate of Savinase activity pH effect of temperature effect of pH 10 11 12 Describe how the effect of temperature on Savinase activity differs from the effect of temperature on a protease that functions in the human stomach. Suggest why laundry detergents that contain Savinase also contain chemicals that dissolve to form an alkaline solution. After washing clothes using laundry detergents, the waste water is sometimes released into the environment. This waste water contains inorganic phosphate ions that are also found in fertilisers. Explain the harmful effect on aquatic life of releasing this waste water into the environment.
5090_w21_qp_22
THEORY
2021
Paper 2, Variant 2
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Amylases are enzymes that are made in specific cells of animals and plants and also by bacteria. In humans, amylase is secreted into the alimentary canal in saliva and in pancreatic juice. Explain what is meant by the term enzyme. Outline two structural features of enzyme molecules. Name both the substrate and product of amylase. substrate product Amylase produced by bacteria can be used as part of an industrial process that converts plants such as corn into biofuel. Biofuels can be used instead of diesel or petrol. The bar chart shows how the activity of amylase is affected by temperature and pH. pH 6.0 pH 6.5 pH 7.0 pH pH 7.5 pH 8.0 temperature 30°C temperature 40°C temperature 50°C temperature 60°C temperature 70°C enzyme activity key: Describe what the data in the bar chart show about the activity of the enzyme and explain why this information is useful for the producers of biofuels. Biofuels can be burnt in vehicle engines. Suggest how biofuels can result in pollution and cause environmental change.
5090_w22_qp_21
THEORY
2022
Paper 2, Variant 1
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is a graph of the temperature in a heap of decomposing organic matter over a period of a month. The temperature changes are caused by the activities of microorganisms in the compost. time / days temperature / °C Name two different types of microorganisms that could cause the changes of temperature shown in . 1. 2. Name a type of microorganism that could not be responsible for the temperature changes and give a reason for your answer. microorganism reason Name a chemical that would be found in the compost in higher concentration at day 30 than at day 1 and explain your answer. chemical explanation The external temperature remained below 30 °C. Explain why the temperature of the compost heap changes between day 0 and day 4. Suggest reasons for the temperature changes between days 16 and 28.
5090_s09_qp_2
THEORY
2009
Paper 2, Variant 0
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Questions Discovered
35