Digestion- foundation level

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This continues until the molecule has been broken down completely

Slide 28

Digestive Enzymes

There are 3 main types of digestive enzymes:

Amylase breaks starch down into glucose.

Protease breaks protein down into amino acids.

Lipase breaks fats down into fatty acids and glycerol

Slide 29

Digestive Enzymes

Starch

Glucose

Protein

Amino Acids

Slide 30

Digestive Enzymes

Glycerol

Fatty Acid

Fatty Acid

Fatty Acid

Glycerol

Fatty Acid

Fatty Acid

Fatty Acid

Lipase

Fat

Fatty Acids

and Glycerol

Slide 31

What factors affect the rate of reaction of enzymes

How do you think you can speed up the rate of an enzymic reaction? (Hint: It’s the same as any other reaction!)

Slide 32

Amylase and Starch Investigation

Amylase enzyme breaks down starch into glucose.

Iodine is the test for starch. If starch is present, iodine turns blue/black.

Watch the demonstration of the experiment then answer the questions on your sheet.

Slide 33

Apparatus

Starch and Iodine

Amylase enzyme

Water at 37˚C

Stopwatch, syringe x 2, thermometer,

Slide 34

Method

Heat the water in the water bath to 37˚C.

Measure out 1cm3 of Starch solution and put it into a test tube.

Put 5 drops of Iodine into the starch. It should turn blue/black.

Put the test tube into the water bath for 2 minutes.

Put 5 drops of Amylase into the starch and start the stopwatch. Stop timing when the blue/black colour disappears.

Slide 35

Results

It took _ seconds for the Iodine and starch solution to turn colourless.

Slide 36

Conclusion

When the starch has been digested into glucose by the amylase the blue/black colour disappears. It took _ seconds for the amylase to digest the starch.

Slide 37

Task

Design an experiment to investigate how to speed up the digestion of starch by amylase.

Use the basic method in your worksheets but add detail to it.

Carry out your investigation safely!