GCSE AQA Biology 2.1 Organisation: Digestion: Which formula shows glucose?
Tic

Question

Which formula shows glucose?
Tick (✓) one box.

C₆H₁₂O₆

CO₂

H₂O

O₂

Which type of enzyme breaks down starch?
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Carbohydrase

Lipase

Protease

This is the method used.

1. Set up the apparatus as shown in Figure 7.

2. After 5 minutes, pour the starch solution into the amylase solution and mix.

3. Remove one drop of the amylase-starch solution mixture and place onto a spotting tile.

4. Immediately add two drops of iodine solution to the amylase-starch solution mixture on the spotting tile.

5. Record the colour of the iodine solution added to the amylase-starch solution mixture.

6. Repeat steps 3 to 5 every minute until the iodine solution is yellow-brown.

Why were the starch solution and the amylase-starch solution left for five minutes before mixing them together?
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So that both solutions could reach 10 °C

So that the student could calculate a mean

So that the student could repeat the investigation

So that the student had time to draw a table of results

How many minutes did it take until the iodine solution and amylase-starch solution mixture was yellow-brown?
Use Figure 8.

_______ minutes

How could a more accurate time be obtained?
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Add more iodine solution to the spotting tile.

Test the mixture with iodine solution every 30 seconds.

Test the mixture with iodine solution for more time.

Use two drops of amylase-starch solution mixture in each test.

Which temperature did the enzyme work quickest at?
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20 °C

35 °C

50 °C

65 °C

Explain why the iodine solution remained blue-black in the investigation at 80 °C.

Which formula shows glucose? Tick (✓) one box - AQA - GCSE Biology - Question 4 - 2021 - Paper 1