Lesson Starter Without using your jotter, try and come up with the highest scoring word from the last lesson on the digestive system. Letters can be used more than once.

Learning Intention To be able to identify where saliva is produced To describe the role of amylase in digestion To find out the optimum temperature for amylase to work at

Set up experiment Instructions Apparatus 3 boiling tubes 1 bottle of starch 1 bottle of amylase 3 labels Goggles Instructions Label 3 boiling tubes with your initials Label the first tube 20°C, the second 37°C and the third 60°C. Add 2 fingers width of Starch into each test tube Add 2 fingers width of amylase into each test tube Leave the 20°C tube at room temperature and place the other 2 in the correct water baths Clear up your chemicals

After 30 minutes.. Test the solutions for the presence of starch Colour change?

Saliva Where is it produced? Lubrication Biological catalysts- enzymes Amylase- degradation enzyme

Amylase and Starch Starch  Maltose Bread- what do you taste? SAM (substrate, enzyme, product) Specific- lock and key Give pupils bread to chew- see if they notice a change in taste

Salivary Amylase (copy) Amylase is an enzyme found in our saliva. An enzyme is a biological catalyst; it speeds up the rate of a reaction. Enzymes are SPECIFIC to one substrate which means they will not work with any other substrate. An enzyme’s active site has a specific shape which fits perfectly with their substrate. They can be compared to a lock and key for this reason. Amylase works specifically on STARCH and speeds up its breakdown into MALTOSE. Enzymes remain UNCHANGED at the end of a reaction; they are not used up. Starch Maltose Amylase

Salivary Amylase: answer in sentences Where is saliva produced? Give 2 functions of saliva What is the role of enzymes? Which enzyme is found in saliva and what does it do? Can this enzyme work on other substances? Explain your answer.

The effect of temperature on Amylase Aim To find out the effect of temperature on the enzyme AMYLASE.

Method Apparatus list Step by step instructions Diagram (drawn with a ruler)

Results Temperature Colour Is starch present? 20°C Blue/Black Yes 37°C Red/Orange No 70°C

Explaining results Low temp Collision theory Inactive (undamaged) Move slow Meet rarely

Explaining results Increasing temp More energy More collisions More reactions Optimum temperature

Explaining results High temp Denatured Lost shape Irreversible

Conclusion (answer in sentences) Does temperature affect enzyme activity? Answer each question for 20°C, 37°C and 70°C What colour change did you see when iodine was added to starch and amylase? Was starch present? How do you know? Explain why starch was or was not present with reference to the state of enzyme

Conclusion At 20°C, the enzyme was inactive. The iodine turned blue/black meaning starch was still present and had not been broken down. The iodine turned blue/black at 60°C meaning starch was still present. The enzyme had become denatured meaning it had lost its shape. The substrate could no longer fit in the active site and so was not broken down. 37°C is the optimum temperature for amylase. We know starch has been broken down as there is no colour change when tested with iodine.