Intervensi biology Form 4 chapter 4

1. INTERVENTION – BIOLOGY CHAPTER 4
CHAPTER 4 : CHEMICAL COMPOSITION OF THE CELL
1. General properties of enzymes.
i. Enzymes are ___________ produced by living cells.
ii. Enzymes are biological __________ which speed up the rate of biochemical
reactions.
iii. Enzymes are ____________ destroyed at the end of a reaction.
iv. Enzyme-controlled reaction is _______________________
lactase
Example : lactose + water glucose + galactose
v. Enzymes are sensitive to changes in temperature, and are very active at an
optimum temperature of ________ oC . It _______________ at high
temperature .
vi. Enzymes are sensitive to ___________ in pH of medium.
vii. Enzyme action is very ________________, One type of enzyme can
catalysed only one type of substrate.
2. The figure represents the action of an enzyme
(a) State two properties of enzyme illustrated by the above figure .
1. ………………………………………………………………………………
2. …………………………………………………………………………….

2. INTERVENTION – BIOLOGY CHAPTER 4
(b) Name two digestive enzymes, their substrate and products.
1. Enzyme : ……………….. Substrate : ………………………Products ……..……..
2. Enzyme : ……………….. Substrate : ………………………Products ……………
(c) Figure below shows the relationship between enzyme activity and temperature
Complete the line to show the effect of increasing the temperature from 10°C to
60°C.
(d) Uses of enzymes
Complete the table below.
Enzymes Usage types Effect
Protease Leather Industry
Digestion Tenderise meat
Cellulase Industrial use Softening vegetables, removing seed coats
Daily use Add to washing powder to remove protein
stains
Digestion Convert fat to fatty acids and glycerol
Amylase Digestion

3. INTERVENTION – BIOLOGY CHAPTER 4
3. The figure shows an experiment set-up to investigate the effect of pH on enzyme
activity. Enzyme Q is found inside the mammalian digestive system.
After 24 hours, the following results were obtained:
pH Reduction in length of egg white strip (mm)
1 7
2 9
3 6
4 3
5 1
6 0
(a) Using the results in the table, plot a graph to show the reduction in length of the egg
white strip against pH of the medium.
(b) Explain the observed reduction in the length of the egg white strip.
……………………………………………………………………………………………….
……………………………………………………………………………………………….
……………………………………………………………………………………………….
……………………………………………………………………………………………….
(c) (i) Name enzyme Q and the products of its action on egg white.
Enzyme Q : …………………………………………………………………….……….
Products: …………………………………………………………………..
(ii) Which part of the mammalian digestive system produce enzyme Q?
…………………………………………………………………………………….…….
4. Below shows the structures of four organic compounds which are found in living cells.

4. INTERVENTION – BIOLOGY CHAPTER 4
(a) (i) Name the structures of compounds X and Z.
W
X : ………………………………………………………………………….
Z : ………………………………………………………………………….
(ii) State the monomer of X and Y.
X : ………………………………………………………………………….
Y : ………………………………………………………………………….
(b) What would happen if pancreatic cells are unable to synthesis compound X?
.……………………………………………………………………………………..
….…………………………………………………………………………………..
(c)(i) In the space below draw and label the structure of the basic unit of organic compound W
(ii) Name two types of organic compound W.
…………………………………………………………………………………..
(iii) State two structural differences between the organic compounds you have
named in (c)(ii).
…………………………………………………………………………………..
…………………………………………………………………………………..
…………………………………………………………………………………..