2.2 Animal tissues, organs and organ systems

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Question 40
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Amylase is an enzyme that digests starch in the human body.

a.

Amylase is a biological polymer. Name the monomer (smaller molecule) that forms this polymer.

[1]
b.

Name two organs in the human digestive system that produce amylase.

[2]
c.

Explain how amylase breaks down starch. Answer in terms of the 'lock and key theory'.

[3]
d.

A student investigated the effect of pH on the activity of amylase.

The student used the following method:

  1. Measure 4 cm34\text{ cm}^34 cm3 of starch solution, 1 cm31\text{ cm}^31 cm3 of buffer solution (to maintain pH), and 0.5 cm30.5\text{ cm}^30.5 cm3 of iodine solution into a test tube. The solution turns blue-black.
  2. Place this test tube and a separate tube containing 2 cm32\text{ cm}^32 cm3 of amylase solution into a water bath at 40∘C40^\circ\text{C}40∘C for 6 minutes.
  3. Add the amylase solution to the starch mixture, stir, and start a stopwatch.
  4. Record the time taken for the blue-black colour to disappear.
  5. Repeat the experiment using buffer solutions of different pH values.

Why did the student leave the tubes in the water bath for 6 minutes before mixing them?

[1]
e.

Name two control variables the student kept constant in this investigation.

[2]
f.

Explain why the blue-black colour disappears when amylase breaks down the starch.

[2]

2.2 Animal tissues, organs and organ systems Questions

  1. GCSE
  2. /Biology
  3. /2.2 Animal tissues, organs and organ systems