Answer all questions in the spaces provided. box
0 1 . 1 The general structure of a fatty acid is RCOOH.
Name the group represented by COOH.
[1
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0 1 . 2 Figure 1 shows the structure of a fatty acid R group.
Figure 1
Name the type of R group shown in Figure 1.
Explain your answer.
[2 marks]
Type of R group
Explanation
0 1 . 3 Describe how you would test for the presence of a lipid in a liquid sample of food.
[2 marks]
3
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box In 1935, scientists suggested a model for the chemical structure of a cell-surface
membrane. Figure 2 shows the membrane structure the scientists suggested.
Figure 2
0 1 . 4 Give one similarity and two differences between the membrane structure shown in
Figure 2 and the fluid-mosaic model of membrane structure.
[3 marks]
Similarity
Difference 1
Difference 2
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box 0 2 . 1 Describe and explain one feature of the alveolar epithelium that makes the epithelium
well adapted as a surface for gas exchange. Do not refer to surface area or moisture
in your answer.
[2 marks]
5
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Doctors measure box the health of lungs by calculating the FEV1:FVC ratio.
• FEV1 is the maximum volume of air exhaled in one second.
• FVC is the maximum volume of air exhaled in one breath.
The minimum FEV1:FVC ratio of healthy lungs is 0.7:1
A man with the lung disease emphysema inflated his lungs fully. He then exhaled as
much of this air as quickly as possible in one breath. Figure 3 shows how the volume
of exhaled air changed during this breath.
Figure 3
0 2 . 2 Use the information provided to determine the FEV1:FVC ratio of this man’s lungs.
Go on to determine how many times greater the minimum ratio of healthy lungs is than
his ratio.
[2 marks]
FEV1:FVC ratio of man’s lungs =
How many times greater?
Question 2 continues on the next page
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0 2 box . 3 Tidal volume is the volume of air inhaled and exhaled during a single breath when a
person is resting. The tidal volume in a person with emphysema is reduced compared
with the tidal volume in a healthy person.
Suggest and explain how a reduced tidal volume affects the exchange of carbon
dioxide between the blood and the alveoli.
[3 marks] [Show Less]