Date: Saturday, 02 December 2023 Enzymes and temperature Learning intention: Understand how enzymes help speed up chemical reactions in the human body Success criteria • Explain why enzymes are specific • Investigate how temperature affects enzyme action • Justify why enzymes are denatured by high temperatures and extremes of pH Do Now Tasks Name a type of food test and the reagent used Explain why it is important that we know what is in our food Suggest how temperature could affect enzymes in the body Explain why enzymes are specific “ Justify why enzymes are denatured by high temperatures and extremes of pH Isabella is turning 1! It is important our bodies maintain an optimum temperature. What might happen if we don’t ? “ ENGAGE Investigate how temperature affects enzyme action Explain why enzymes are specific EXPLORE Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes Each of your cells can have a hundred or more chemical reactions going on inside it at any one time. Each one of these different types of reaction is controlled by a different enzyme. Enzymes do not change reactions in any way. They just make reactions happen faster. They do this by lowering the ‘activation energy’ for the reaction. Explain why enzymes are specific EXPLORE Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes Enzymes are denatured by temperature and pH Explain why enzymes are specific EXPLORE Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes Biological reactions are affected by the same factors as any other chemical reactions: • Concentration • Surface Area • Temperature However, in a living organism an increase in temperature will only increase a reaction up to a certain point. Explain why enzymes are specific EXPLORE Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Enzymes and temperature Task: Watch the video on the next slide demonstrating an investigation into the affect of temperature on enzymes. Write a full method for the experiment. Self-assess using PURPLE pen. Record the results of the experiment. Write a conclusion based on the results. Challenge: Justify the science behind your conclusion. Extra challenge: Evaluate the investigation. Include suggestions for improvements and justify your suggestions. Explain why enzymes are specific Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Explain why enzymes are specific EXPLAIN Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes The affects of temperature – Practical Set up water baths at various temperatures (e.g. 0°C, 20°C, 40°C, 60°C and 80°C). Add starch solution to 5 test tubes. Add amylase solution to another 5 test tubes. Place one starch and one amylase test tube into each water bath for 5 minutes - to allow the enzyme and substrate to reach the desired temperature. Place 1 drop of iodine into each dimple on a spotting tile. Add the amylase to the starch in the 0°C water bath. Explain why enzymes are specific EXPLAIN Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes The affects of temperature – Practical Start the timer. Every minute remove a sample of the starch-amylase solution and add it to a drop of iodine on the spotting tile. Repeat step 8 until the iodine no longer changes colour - meaning that there is no starch present, in other words the amylase has broken all starch down. Repeat steps 6-9 for each of the temperatures. Record results. Draw a graph to show the time taken for starch to be digested at different temperatures. Explain why enzymes are specific Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Task: Describe each graph then explain the effects Identify at which pH pepsin works best. of different temperature and pH on enzymes. Effect of pH on enzyme activity 0 10 20 30 40 50 Temperature (⁰C) 60 Relative activity Rate of reaction Relative activity Effect of temperature on an enzyme Explain what happens to the enzyme activity as the pH increases. pepsin 0 2 4 6 pancreatic amylase 4 6 Identify at which pH pancreatic amylase works best. 8 10 Challenge: Justify why this change happens. Support: In your description include these key words: • Optimum • Rate • Denatured Explain why enzymes are specific Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Feedback to feedforward: Swap your work with someone else on your table. Check their answers are correct. Check their work and identify WWW and EBI. You have 4 minutes. What went well: Identify good knowledge and understanding. Even better if: Identify and suggest areas for improvement. Challenge: Suggest what other factors could affect the function of enzymes Explain why enzymes are specific Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Feedback to feedforward: Use your feedback to make improvements to your work, using PURPLE pen. Challenge: Suggest what other factors could affect the function of enzymes Explain why enzymes are specific EXTEND Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH The need for enzymes Different enzyme’s have a different optimum pH. Suggest what type of conditions you think the enzymes in the stomach prefer. Explain why enzymes are specific Investigate how temperature affects enzyme action Justify why enzymes are denatured by high temperatures and extremes of pH Task: Draw a single diagram (no words) to demonstrate something you have learnt today. Challenge: Create a question that you can answer, but make it as difficult as you can for others in the class. Post it in the chat on Teams for others to answer.
