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PANITIA BIOLOGI NEGERI KELANTAN 2007
CHAPTER 4 : CHEMICAL COMPOSITION IN THE CELL
Multiple Choice Questions:
For question 4-1 to 4-44, each question is followed by four alternative options A,B,C and D.
Choose one correct answer for each question and blacken the corresponding space in your
objective answer
4.1 : Understanding The Chemical Composition Of The Cell
1. Which of these elements is not found in large amounts in the cell ?
A. Sulphur
B. Oxygen
C. Carbon
D. Hydrogen
2.
Which compound has the characteristics listed above ?
A. Lipid
B. Water
C. Enzyme
D. Protein
3. What is the importance of nucleic acids?
A. Build cells during growth
B. Main source of energy in cells
C. Required for the synthesis of antibodies
D. Carry genetic material
4. Which of the following is not a function of water?
A. Provides a moist surface for the diffusion of gases
B. Facilitates the movement of joints
C. An insulator of heat in the body
D. Facilitates the hydrolysis of food by enzymes
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Medium for chemical reactions in cell
Maintains osmotic pressure
PANITIA BIOLOGI NEGERI KELANTAN 2007
5. The common chemical compounds in cells are
I. Carbohydrate
II. Nucleic acids
III. Cellulose
IV. Proteins
A I and II only
B. II and IV only
C. I, II and III only
D. I, II and IV only
4.2 : Understanding Carbohydrate
6. Starch is made of
A. Glucose
B. Sucrose
C. Maltose and fructose
D. Glycerol and glucose
7. What is the major function of monosaccharide in animals?
A. Regulates metabolism
B. Acts as structural material
C. Acts as food reserve
D. Releases energy
8. Which of the following is not a disaccharide?
A. Sucrose
B. Fructose
C. Lactose
D. Maltose
9. Which of the following monosaccharide combinations produces sucrose?
A. Glucose + fructose
B. Glucose + galactose
C. Fructose + galactose
D. Glucose + glucose
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10. What is the monomer of carbohydrates?
A. Glycerol
B. Nucleotide
C. Polysaccharide
D. Simple sugar
11. Plants usually store their excess carbohydrates in the form of
A. glycogen
B. starch
C. glucose
D. cellulose
12. The main carbohydrates food reserve in liver cells is
A. glucose
B. glycogen
C. lactose
D. starch
13. The formula for disaccharide is
A. C2H10O11
B. C6H12O6
C. C12H22O11
D. (C6H12O6)n
14. Which of the following are reducing sugars ?
I. Glucose
II. Fructose
III. Sucrose
IV. Lactose
A. I and II only
B. III and IV only
C. I, II and IV only
D. I, II, III and IV
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PANITIA BIOLOGI NEGERI KELANTAN 2007
15. Which of the following elements are present in carbohydrates ?
I. Carbon
II. Hydrogen
III. Nitrogen
IV. Oxygen
A. I and III only
B. I, II and IV only
C. II, III and IV only
D. I, II, III and IV
16. Which of the following carbohydrates are examples of polysaccharides ?
I. Glycogen
II. Starch
III. Cellulose
IV. Galactose
A. I, II and III only
B. I, II and IV only
C. II, III and IV only
D. I, II, III and IV
4.3 : Understanding Protein
17. Protein is made up of
A. fatty acids
B. amino acids
C. nucleic acids
D. mineral salts
18. Haemoglobin is an example of a
A. primary structure of protein
B. secondary structure of protein
C. tertiary structure of protein
D. quaternary structure of protein
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19. Amino acids are linked together to form a
A polypeptide
B. polynucleotide
C. polysaccharide
D. polyribosome
20. A dipeptide can be broken down into amino acids by the process of
A. condensation
B. heating
C. acids addition
D. hydrolysis
21. What is the type of protein structure that both enzymes and hormones have ?
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
22. The process when two amino acids are joined together is called
A. hydrolysis
B. deamination
C. condensation
D. synthesis
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23. Diagram 4.1 shows the molecular structure of proteins.
Figure 1
DIAGRAM 4.1
Which protein structure do X, Y and Z belong to?
24. Which of the following are functions of proteins ?
I. Formation of some hormones
II. Enzyme production
III. Tissue repair and building body substances
IV. Energy production
A. I and II only
B. I, II and III only
C. II, III and IV only
D. I, II, III and IV
25. Which of the following elements are found in proteins?
I. Carbon
II. Nitrogen
III. Sulphur
IV. Phosphorus
A. I and II only
B. III and IV only
C. I, II and IV only
D. I, II, III and IV
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X Y Z
A.
B.
C.
D.
Tertiary
Primary
Secondary
Quaternary
Quaternary
Secondary
Primary
Tertiary
Primary
Tertiary
Quaternary
Secondary
X Y Z
PANITIA BIOLOGI NEGERI KELANTAN 2007
26. Which of the following statements are true about essential amino acids?
I. They cannot be synthesised by human body from other compounds.
II. They must be taken in with food.
III. They include lysine and valine
IV. They are derived from other amino acids.
A. I and II only
B. III and IV only
C. I, II and IV only
D. I, II and III only
4.4 : Understanding Lipid
27. Among the elements in the cell, which are found in lipid ?
A. Carbon, nitrogen and oxygen
B. Carbon, hydrogen and oxygen
C. Carbon, hydrogen and sulphur
D. Carbon, nitrogen and phosphorus
28. How many fatty acids chains are in a phospholipids molecule ?
A. One
B. Two
C. Three
D. Four
30. A lipid is formed by condensation of
A. Amino acids and glucose
B. Amino acids and glycogen
C. Fatty acids and glycogen
D. Fatty acids and glycerol
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PANITIA BIOLOGI NEGERI KELANTAN 2007
31. Which of the following are lipids ?
I. Steroids
II. Triglycerides
III. Oils
IV. Waxes
A. I and II only
B. I, II and III only
C. II, III and IV only
D. I, II, III and IV
32. Saturated fats
I. contains fatty acids which do not have double bonds between the carbons.
II. Contain fatty acids with double bonds between the carbon atoms.
III. are liquid at room temperature.
IV. have a higher content of cholesterol
A. I and IV only
B. II and III only
C. I, III and IV only
D. II, III and IV only
33. Which of the following is not true about the difference between saturated fats and
unsaturated fats ?
Saturated fat Unsaturated fat
A. Of animal origin Of vegetable origin
B. Usually in solid form or almost solid at
room temperature
Usually in liquid form at room
temperature
C.They are found in butter and cheese
They are found in most vegetable
products and oils
D. They have one or more double bonds
between their carbon atoms.
They do not have double bonds
between their carbon atoms
34. Diagram 4.2 shows a structure of one lipid molecule.
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PANITIA BIOLOGI NEGERI KELANTAN 2007
DIAGRAM 4.2
The part labelled Q represents
A. phosphate
B. glycerol
C. fatty acids
D. amino acids
35. Lipid is needed to form P while cellulose is needed to form Q. What are P and Q ?
Compound P Compound Q
A. Protoplasm Cell wall
B. Plasma membrane Cell wall
C. Cell wall Protoplasm
D Cell wall Plasma membrane
4.5 : Understanding Enzyme
36. Enzymes are made up of
A. carbohydrate
B. proteins
C. lipids
D. dietary fibres
37. Which of the following is not true about general characteristic of enzyme?
A. Enzyme action is specific
B. Active at temperatures exceeding 60oC
C. Sensitive to changes in pH
D. Accelerates the rate of biochemical reactions
38. Diagram 4.3 shows a stained shirt being washed by detergent containing pepsin at
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PANITIA BIOLOGI NEGERI KELANTAN 2007
20oC. The result was obtained after 1 hour interval.
DIAGRAM 4.3
The shirt of the same material was repeatedly washed at 37oC. Which of the following
shows the result after 1 hour?
B.
D.
39. The active site of an enzyme is
A. specific to its substrate
B. identical to the active sites of other enzymes
C. complementary to its substrate
D. denatured at the end of a chemical reaction
40. Which of the following statements regarding enzymes is true?
A. All enzymes in living organisms have an optimum temperature of 37°C.
B. Enzymes increase the activation energy for the reactions they catalyses.
C. Enzymes are denatured at 0°C.
D. Enzymes function as organic catalysts.
41. Which organelle is involved in the production of extracellular enzymes ?
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After 1 hour
A
B
C
D
PANITIA BIOLOGI NEGERI KELANTAN 2007
A. Golgi apparatus
B. Mitochondrion
C. Chloroplast
D. Smooth endoplasmic reticulum
42. Which of the following is correct about the types of enzymes produced for P and Q?
P Q
A
B
C
D
Intracellular
Extracellular
Intracellular
Extracellular
Extracellular
Intracellular
Intracellular
Extracellular
43. A suitable enzyme that can be used for these activities is
A. cellulase
B. protease
C. zymase
D. amylase
44. Diagram 4.4 shows the mechanism of enzyme action. Which property of enzyme is
shown in the diagram?
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P – enzymes which are synthesised in the cell but secreted from the cell to work externallyQ – enzymes which are synthesised and retained in the cell for use of the cell itself
Remove germ from wheat Separate agar from seaweed
DIAGRAM 4.4
PANITIA BIOLOGI NEGERI KELANTAN 2007
A. Enzyme structure is denatured by extremes of pH.
B. Temperature affects the rate of enzyme reaction.
C. Enzyme reaction is non-specific.
D. Structure of enzyme remains unchanged at the end of the reaction.
Structured Items
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PANITIA BIOLOGI NEGERI KELANTAN 2007
Answer all questions. Write your answer in the spaces provided in the question paper
4.1: Understanding The Chemical Composition Of The Cell
4.2: Understanding Carbohydrate
(1) Diagram 4.4 shows the structures of 3 examples of polysaccharides P, Q and R.
DIAGRAM 4.4
(a) Identify the molecules labeled P, Q and R.
[3 marks]
(b) Where can the molecules be found
[3 marks]
(c) Structure P can be broken down into a simpler form by a process. What is the
process involved?
[1 mark]
(d) (i) State one similarity in the 3 polysaccharides
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PANITIA BIOLOGI NEGERI KELANTAN 2007
(ii) What is the main difference between structures P and Q?
[2 marks]
(e) Sucrose and lactose are examples of disaccharides that can be formed from
condensation of monosaccharide. What are the monosaccharide that form
Sucrose :
Lactose :
[2 marks]
(f) Briefly describe how to test for the presence of reducing sugar in an unknown
sample of food.
[1 mark]
4.3 : Understanding Protein
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PANITIA BIOLOGI NEGERI KELANTAN 2007
2. Diagram 4.5 shows the organelle involved during the synthesis and secretion of
protein in animal cell.
DIAGRAM 4.5
(a) Name the organelles labeled X, Y and Z.
[3 marks]
(b) State the function of X and Y
[2 marks]
(c) Molecule P is produced from the protein excreted by the cell.
(i) What is the type of structure shown by the molecule?
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Molecule P
X
Y
Z
PANITIA BIOLOGI NEGERI KELANTAN 2007
(ii) Give one example of the structure mentioned in c(i).
[2 marks]
(d) (i) Proteins are made from amino acids, name two types of amino acids
involved.
[2 marks]
(ii) Briefly, explain the meaning of the answer in d(i).
[2 marks]
4.4 : Understanding Lipid
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3. Diagram 4.6 shows the structure of a lipid molecule.
DIAGRAM 4.6
(a) Name the parts X and Y.
[2 marks]
(b) (i) What is the chemical reaction P that takes place to form the bonds
between X and Y?
[1 mark]
(ii) What is product Q formed during this reaction?
[1 mark]
(c) (i) What is the structural difference between a phospholipid molecule and
the lipid molecule shown in the figure above?
[1 mark]
(ii) What is the function of phospholipids in cells?
[1 mark]
(d) One of the main types of lipid is fat.
(i) State two types of fat
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[2 marks]
9ii) State two differences between the types of fat named in d(i).
[2 marks]
(e) Explain why a daily intake of a diet rich in fats is bad for health.
[2 marks]
4.5 : Understanding Enzyme
4. Diagram 4.7 shows the organelles involved in the production of extracellular enzymes.
DIAGRAM 4.7
(a) Name the organelles labelled T and U.
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S
T
R
U
PANITIA BIOLOGI NEGERI KELANTAN 2007
[2 marks]
(b) State the function of organelle labelled R
[1 mark]
(c) Using an example and place produced, explain the term of extracellular
enzyme.
[3 marks]
(d) Based on the organelles shown in Diagram 4.7, explain how extracellular
enzymes are produced.
[3 marks]
(e) Diagram 4.8 shows the action of an enzyme and its substrate.
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DIAGRAM 4.8
Explain the mechanism of enzyme action.
Max : 3 marks]
5. Diagram 4.9 shows a graph represent the effect of temperature on the rate reaction of
enzyme P.
DIAGRAM 4.9
(a) What is the optimum temperature for enzyme P ?
[1 mark]
(b) Describe the effect of different temperature on the rate of enzyme reaction.
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Temperature (oC)
PANITIA BIOLOGI NEGERI KELANTAN 2007
[max: 4 marks]
(c) Enzymes are widely used in the household & industries. Explain how enzymes
act in :
(i) Helping to cook meat.
(i) Extracting agar from seaweed
[4 marks]
(d) State three factors besides temperature that affect the enzymes activity.
[3 marks]
Essay Items
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PANITIA BIOLOGI NEGERI KELANTAN 2007
Answer all questions
4.1 : Understanding The Chemical Composition Of The Cell
4.2 : Understanding Carbohydrate
4.3 : Understanding Protein
4.4 : Understanding Lipid
1.
(a) Explain the importance of organic compounds like carbohydrate and protein in
a cell. [10 marks]
(b) (i) Name two types of nucleic acids found in living cells. [2 marks]
(ii) Compare and contrast
saturated fats and unsaturated fats
Essential amino acids and non essential amino acids [8 marks]
4.5 : Understanding Enzyme
2. (a) (i) What is an enzyme? [2 marks]
(ii) Explain the characteristics of enzymes from the ‘lock and key’
hypothesis
(iii) Describe how an enzyme-controlled reaction is affected by pH.
[4 marks]
(b) Enzymes can be extracted and separated from cells in order to be used.
Explain how the enzymes can be used in daily life and industry.
[10 marks ]
4-22
There are several components in cells which form organic and inorganic
compounds. Organic compounds normally found in cells are carbohydrate,
proteins, lipids and nucleic acids. Each compound plays an important role in
the cell.