Key words: Denatured, Optimum temperature, PH Enzymes Key words: Denatured, Optimum temperature, PH Starter: Key word bingo Pick 9 key words: Active site Products Enzyme Denature Substrate Catalyst Enzyme-substrate complex Proteins Lock and key theory Amino acids pH temperature

The big picture: “How does temperature and pH effect enzymes?” Learning outcomes To describe how temperature and pH effect enzymes. To investigate what is meant by the “optimum” temperature. To evaluate how the rate of reaction is affected by denaturing of an enzyme.

pH and temperature If enzymes are put in the wrong conditions (high temperature of the wrong pH) they are denatured. This means the shape of the active site is damaged so the reaction stops.

TUNE DREAD PUMP HI TOM IMPROMTU MUTATE ERE Unscramble the words! TUNE DREAD PUMP HI TOM IMPROMTU MUTATE ERE https://www.youtube.com/watch?v=XTUm-75-PL4 – enzymes- a fun introduction https://www.youtube.com/watch?v=8WFo9iW5gQo – denaturing video

Task Draw a diagram to show what denatured means. Explain how this could happen due to temperature or pH. Extra challenge: What happens to the rate of reaction if an enzyme is denatured? Use a graph to help you explain your answer.

Investigation to identify which temperature amylase works best at Amylase is an enzyme which breaks down starch into sugars. If amylase has worked there will be no starch present (iodine stays brown). If amylase has not worked the starch will cause the iodine to turn black.

What temperature does amylase work best at? You will be using a water bath at different temperatures – be careful they could be hot. You will need 3 test tubes label the 1, 2,3 add your initials. 2. Use the syringe/measuring cylinder to put 5ml of starch solution into each boiling tube. Put one tube in the hot water bath, one in the ice and one in the medium bath. Leave for 5 minutes. 4. Add 1ml of amylase to each tube (use squeezy pipette). Leave for 2 minutes. 5. Add a few drops of iodine to each tube. Record the colour in your books.

Investigation to identify which temperature amylase works best at – steps to success Prediction – in full sentences make a prediction of what you think will happen and why Results Table Risk assessment Equipment Hazard when using Risk of injury How to prevent injury Temp of starch (oC) Colour after iodine added Was starch broken down?

Comic strip Produce a comic strip to explain how enzymes can be effected by temperature and pH. Key words to include: Optimum, temperature, pH, denatured, active site, rate of reaction

How can enzymes be denatured? 1 2 3 How can enzymes be denatured? 6 5 4

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