F. 4 ____
Name: __________________________ (
)
Date: _______________
F.4 Biology
Ch.7 Nutrition in humans
Worksheet 1
1.
A student used the following set-up to compare the fat digestion of full fat milk and half fat fresh
milk:
(a)
Write a simple word equation of fat digestion.
(3 marks)
a.
Fat
(b)

b.
+
c.
Two test tubes, each with a different type of milk, were prepared. The colour of each mixture was
recorded immediately after the addition of lipase solution, and then monitored until there was no
more change in colour. The colours of the mixtures at the beginning and the end are shown in
Diagrams I and II respectively:
(i)
Which of the following is the independent variable in this investigation?
(1 mark)
A.
B.
C.
______
Type of milk
Colour of the mixture after the experiment
Full fat milk and half fat fresh milk
(ii)
Describe the results of this investigation.
(2 marks)
Tube A:
Tube B:
(iii)
(c)
Which test tube (A or B) was the one with full fresh milk? Explain your answer.
(4 marks)
The experiment is repeated. 1mL of lipase solution and bile salt is added into the tube A.
Compare the time taken for the mixture to change its colour with and with bile salts. Explain your
answer.
(4 marks)