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1.
2.
Which enzyme removes the RNA primer during replication?
A.
RNA primase
B.
DNA polymerase I
C.
DNA ligase
D.
Helicase
Consider the metabolic pathway shown below.
A
1
B
2
C
3
D
4
E
If there is end-product inhibition, which product (B to E) would inhibit which enzyme (1 to 4)?
3.
4.
Product
Enzyme
A.
C
4
B.
B
3
C.
B
4
D.
E
1
Which is not a primary function of protein molecules?
A.
Hormones
B.
Energy storage
C.
Transport
D.
Structure
Which two colours of light does chlorophyll absorb most?
A.
Red and yellow
B.
Green and blue
C.
Red and green
D.
Red and blue
1
5.
6.
7.
8.
9.
Which is not a product of the Krebs cycle?
A.
CO2
B.
NADH + H+
C.
Pyruvate
D.
ATP
How many ATP molecules (net yield) are produced per molecule of glucose as a direct result of
glycolysis?
A.
2
B.
4
C.
10
D.
38
What happens during muscle contraction?
A.
Both actin and myosin filaments shorten.
B.
Na+ ions are taken up by the sarcoplasmic reticulum.
C.
The actin and myosin filaments slide over each other.
D.
Cross bridges remain attached to the filaments.
Which way do the protons flow when ATP is synthesized in mitochondria?
A.
From the inner matrix to the intermembrane space
B.
From the intermembrane space to the inner matrix
C.
From the intermembrane space to the cytoplasm
D.
From the cytoplasm to the intermembrane space
What can reduce the effect of a competitive inhibitor of an enzyme?
A.
Decrease the temperature at which the reaction takes place.
B.
Increase the temperature at which the reaction takes place.
C.
Increase the substrate concentration.
D.
Add a non-competitive inhibitor.
2
10.
11.
12.
What accumulates in the inter-membrane space of the mitochondrion during electron transport?
A.
ATP
B.
Electrons
C.
Protons (hydrogen ions)
D.
Oxygen
The diagram below shows a channel protein in a membrane. Which parts of the surface of the
protein would be composed of polar amino acids.
A.
I and II only
B.
II and III only
C.
III and IV only
D.
I and IV only
What effect do enzymes have on the activation energy of exergonic and endergonic reactions?
Activation energy of Activation energy of
exergonic reactions endergonic reactions
A.
increases
increases
B.
decreases
decreases
C.
increases
decreases
D.
decreases
increases
3
13.
14.
15.
16.
What is the sequence of stages during the conversion of glucose into pyruvate in glycolysis?
A.
Lysis
phosphorylation of sugar
oxidation
B.
Lysis
oxidation
C.
Phosphorylation of sugar
lysis
D.
Phosphorylation of sugar
oxidation
phosphorylation of sugar
oxidation
lysis
How is the proton gradient generated in chloroplasts during photosynthesis?
A.
Flow of electrons from carrier to carrier in the thylakoid membrane causes pumping of
protons across the thylakoid membrane.
B.
Light causes protons to flow through protein channels in the thylakoid membrane.
C.
Light splits water molecules in the stroma, causing the release of protons.
D.
Protons are pumped across the thylakoid membrane using energy from ATP.
Why is the action spectrum for photosynthesis similar to the absorption spectra of
photosynthetic pigments?
A.
Photosynthetic pigments have the same optimum temperature as the enzymes used in
photosynthesis.
B.
Plants absorb the same photosynthetic pigments for use in photosynthesis.
C.
Only wavelengths of light absorbed by pigments can be used in photosynthesis.
D.
The amount of energy absorbed by photosynthetic pigments is equal to the activation
energy for photosynthesis.
To which parts of the deoxyribose molecule do phosphates bind in DNA?
V
CH2 OH
I
O
H
IV
H
H
H
OH
II
OH
H
III
4
17.
A.
I and V
B.
III and IV
C.
II and III
D.
III and V
In the enzyme controlled pathway shown below, which compound is most likely to inhibit
enzyme (w)?
Precursor
18.
A.
I
B.
II
C.
III
D.
IV
enzyme
enzyme
enzyme
enzyme
w
x
y
z

I

II

III

IV
How many molecules of acetyl CoA (ethanoyl CoA) does the oxidation of the fatty acid stearic
acid produce?
CH 3
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
Stearic acid
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
CH 2
COOH
A.
2
B.
6
C.
9
D.
18
(1)
5
19.
20.
21.
A biochemist isolated and purified molecules needed for DNA replication. When some DNA
was added replication occurred, but the DNA molecules formed were defective. Each consisted
of a normal DNA strand paired with segments of DNA a few hundred nucleotides long. Which
of the following had been left out of the mixture?
A.
DNA ligase
B.
Helicase
C.
Nucleotides
D.
DNA polymerase
Which of the following produce ATP in mitochondria?
A.
The movement of protons from the matrix to the intermembrane space
B.
The movement of protons from the intermembrane space to the cytoplasm
C.
The splitting of water molecules and the movement of electrons to oxygen
D.
The movement of protons from the intermembrane space to the matrix
In an electron micrograph, a DNA molecule appears 1 mm wide. The magnification of the
micrograph is 500 000. What is the width of the DNA molecule?
A.
0.5 nm
B.
2 nm
C.
0.5 m
D.
2 m
6
22.
What is a difference between the sense and antisense strands of DNA?
A.
Nucleotides are linked to the sense strand by hydrogen bonding during transcription, but
not to the antisense strand.
B.
The sense strand has the same base sequence as tRNA, but the antisense strand does not.
C.
Nucleotides are linked to the antisense strand by hydrogen bonding during transcription,
but not to the sense strand.
D.
The antisense strand has the same base sequence as mRNA but the sense strand does not.
(Total 1 mark)
23.
The graphs below show the energy changes during endergonic and exergonic reactions, with
and without enzymes.
Which line represents an endergonic reaction, without an enzyme?
A.
I
B.
II
C.
III
D.
IV
7
24.
Which diagram represents the process of cyclic photophosphorylation?
25.
What is the advantage of having a small volume inside the thylakoids of the chloroplast?
26.
A.
A high proton concentration is rapidly developed.
B.
A high electron concentration is rapidly developed.
C.
Photosynthetic pigments are highly concentrated.
D.
Enzymes of the Calvin cycle are highly concentrated.
What is one role of the element phosphorus?
A.
It forms part of the structure of amino acids.
B.
It forms part of the structure of fatty acids.
C.
It forms part of the structure of ribose.
D.
It forms part of the structure of nucleotides.
8
27.
The reaction below shows the energy changes in a chemical reaction.
What would happen to the changes in energy if this reaction was controlled by an enzyme?
28.
29.
A.
I would increase.
B.
II would decrease.
C.
I and IV would decrease.
D.
II and III would decrease.
Which of the following reactions is an oxidation reaction?
A.
Pyruvate  Acetate + CO2
B.
FAD + 2H+ + 2e–  FADH2
C.
Ribulose bisphosphate + CO2  2  Phosphoglycerate
D.
NADP+ + 2H+ + 2e–  NADPH + H+
The average surface area for the inner membranes of mitochondria in a epithelial cell is 40 m2
g–1. The surface area of the inner membrane of mitochondria from heart muscle cells is over 200
m2 g–1.
What is the reason for the large surface area of the inner membranes of the mitochondria in the
heart muscle cells?
A.
They contain enzymes to hydrolyse ADP and inorganic phosphate to ATP.
B.
They contain enzymes to oxidize ADP and inorganic phosphate to ATP.
C.
They contain enzymes to reduce ADP and inorganic phosphate to ATP.
D.
They contain enzymes to condense ADP and inorganic phosphate to ATP.
9
30.
31.
32.
33.
According to the induced fit model of enzyme function, which of the following statements is
correct?
A.
Active sites on enzymes are specific to a single substrate.
B.
The shape of the active site can be changed by the binding of an allosteric inhibitor.
C.
The binding of the substrate changes the shape of the active site slightly.
D.
Competitive inhibitors can change the shape of enzymes.
During which process are oxygen molecules directly involved during cellular respiration?
A.
Glycolysis
B.
Krebs cycle
C.
Oxidation of pyruvate to acetyl CoA
D.
Accepting electrons at the end of the electron transport chain
Where is an anti-codon located?
A.
tRNA
B.
mRNA
C.
DNA
D.
Ribosomes
Which graph shows the effect of increasing carbon dioxide concentration (CO2 ) on the rate of
photosynthesis?
A.
B.
10
C.
D.
11
34.
35.
What is the function of DNA polymerase I?
A.
To add appropriate nucleotides in the 3′  5′ direction
B.
To remove the RNA primers and replace them with DNA
C.
To join together the Okazaki fragments
D.
To join together both strands of DNA to the histones
Which statement describes how allosteric enzymes work?
Competitive
inhibition
Reversible
End-product
inhibition
Active and
inactive forms
A.
B.
C.
D.
Key:
36.
= yes
= no
Which diagram shows how enzymes change the activation energy in an endergonic reaction?
A.
B.
X
Y
X
Y
Energy
Energy
Progress of reaction
C.
Progress of reaction
D.
Y
X
X
Y
Energy
Energy
Progress of reaction
Key: X = without enzyme
Progress of reaction
Y = with enzyme
12
37.
38.
What is the “link reaction” in eukaryotic respiration?
A.
Pyruvate joining with coenzyme A to produce CO2 and NADH + H+
B.
Oxidation of NADH to yield electrons and protons
C.
Acetyl coenzyme A combining or joining with a C4 compound to give C6 + coenzyme A
D.
Passage of acetyl coenzyme A through the mitochondrial membrane
How are photosynthesis and aerobic respiration similar?
ATP synthetase enzyme
NADH + H+
Electron transport chain
A.
B.
C.
D.
Key:
39.
= both have or use this
= both do not have or use this
In the graph below which line shows an action spectrum of photosynthesis?
A
D
B
C
Relative rate of
photosynthesis
400
500
600
700
Wavelength / nm
(Total 1 mark)
13
40.
The drawing below shows a short section of a DNA molecule. What is labelled by I, II and III?
I
II
III
41.
42.
I
II
III
A.
3′ end
purine
hydrogen bond
B.
5′ end
pyrimidine
covalent bond
C.
3′ end
pyrimidine
hydrogen bond
D.
5′ end
purine
covalent bond
Which combination of changes describes biological oxidation?
Electrons
Oxygen
Hydrogen
A.
loss
gain
loss
B.
loss
loss
gain
C.
gain
loss
gain
D.
gain
gain
loss
Within the mitochondria, what compound is produced through oxidation of fatty acids?
A.
Acetyl-CoA
B.
Acetylcholine
C.
Oxaloacetate
D.
Pyruvate
14
43.
Which of the following features is/are present in mitochondria but not in chloroplasts?
44.
I.
DNA and ribosomes
II.
Outer and inner membranes
III.
Cristae
A.
I only
B.
II only
C.
III only
D.
I and III only
Which diagram represents the action spectrum of photosynthesis?
B.
100
100
80
80
Relative rate of
photosynthesis
Relative rate of
photosynthesis
A.
60
40
20
0
60
40
20
0
400
500
600
Wavelength
700
500
600
Wavelength
700
400
500
600
Wavelength
700
D.
100
100
80
80
Relative rate of
photosynthesis
Relative rate of
photosynthesis
C.
400
60
40
20
0
60
40
20
0
400
500
600
Wavelength
700
15
45.
Which of the following diagrams is the structure of ribose?
A.
O
HOH 2C
H
H
C.
H
C
C
OH
OH
46.
C
OH
OH
D.
H
OH
C
OH
O
H
H
C
OH
H
C
C
H
OH
HOH2 C
C
C
H
H
OH
O
HOH 2C
CH 2OH
C
C
C
H
B.
OH
O
H
C
C
CH 2OH
H
H
C
C
C
H
OH
H
H
OH
The graph below shows enzyme activity plotted against temperature. What is happening at point
I?
I
Enzyme activity / arbitrary units
Temperature /  C
A.
The enzyme is being denatured.
B.
pH changes are slowing the reaction.
C.
The concentration of the substrate remains constant.
D.
The reaction is increasing in speed.
16
The diagram below shows the bases on a short section of DNA during replication. Identify the
sequence of bases on the new complementary strand labelled I in the diagram.
I
A
G
A
T
C
47.
48.
49.
A.
CTAG
B.
CUAG
C.
TCGA
D.
AGCT
What are the end products of aerobic cell respiration?
A.
Carbon dioxide and ethanol
B.
Lactate and ATP
C.
Water, ATP and oxygen
D.
Water, carbon dioxide and ATP
What occurs in the induced fit model for enzyme catalysed reactions?
A.
There is an exact fit between a specific substrate and a specific enzyme.
B.
The enzyme can change shape to accommodate the substrate.
C.
The substrate can change its shape to fit a number of enzymes.
D.
Other substrates can bind away from the active site.
17
50.
51.
52.
What is a nucleosome?
A.
The protein core of a chromosome
B.
Histone proteins and DNA
C.
A chain of ribosomes
D.
The material within the nuclear membrane
What is an intron?
A.
The 3  5 strand of a DNA double helix
B.
The 5  3 strand of a DNA double helix
C.
A section of mRNA removed before translation
D.
A tRNA with a start anticodon
The diagram below shows the light independent stage of photosynthesis (the Calvin Cycle).
Glucose
I
Ribulose
bisphosphate
(RuBP)
CO2
II
Triose Phosphate
(TP)
Glycerate 3–Phosphate
(GP)
III
Where is energy, from ATP generated during the light dependent stage, used in this cycle?
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
18
53.
54.
What is the key function of acetyl CoA in cellular respiration?
A.
Involved in carbohydrate and fatty acid metabolism
B.
Used in anaerobic respiration to oxidize pyruvate
C.
Introduces amino acids into the Krebs cycle
D.
Used as a hydrogen carrier in the link reaction
Which events take place in DNA replication?
I.
II.
III.
55.
Formation of messenger RNA
Unwinding of DNA double helix
Formation of complementary strands by DNA polymerase
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
Which are the correct directions of the following processes?
Replication
Transcription
Translation
A.
5’ to 3’
3’ to 5’
3’ to 5’
B.
3’ to 5’
5’ to 3’
5’ to 3’
C.
5’ to 3’
5’ to 3’
5’ to 3’
D.
3’ to 5’
3’ to 5’
3’ to 5’
19
57.
Which stage of translation is illustrated by the diagram below?
A.
Termination
B.
Initiation
C.
Translocation
D.
Elongation
The diagram below shows the energy levels of a reaction in the presence or absence of an
enzyme. What is the best explanation of the different energy levels labelled I, II and III?
I
Energy level
56.
II
Energy of
reactants
III
Energy of products
Progress of reaction
I
II
III
20
58.
A.
Absence of an enzyme
Presence of an enzyme
Endergonic reaction
B.
Presence of an enzyme
Absence of an enzyme
Exergonic reaction
C.
Absence of an enzyme
Presence of an enzyme
Exergonic reaction
D.
Presence of an enzyme
Absence of an enzyme
Endergonic reaction
The diagram below shows the three stages of glycolysis. Which processes are indicated by I, II
and III?
6-carbon glucose
I
6-carbon glucose phosphate
II
3-carbon
sugar phosphate
3-carbon
sugar phosphate
III
3-carbon
pyruvate
3-carbon
pyruvate
-
I
II
III
21
59.
A.
Lysis
Phosphorylation
Oxidation and ATP
formation
B.
Oxidation and ATP
formation
Phosphorylation
Lysis
C.
Phosphorylation
Lysis
Oxidation and ATP
formation
D.
Phosphorylation
Oxidation and ATP
formation
Lysis
Which of the following molecules is ribose?
A.
B.
C.
D.
22
60.
61.
Why are the messenger RNA molecules received by eukaryotic ribosomes shorter than the
messenger RNA molecules formed by transcription of DNA?
A.
Base deletion mutations make the mRNA shorter.
B.
Start codons are not at the end of the mRNA molecule.
C.
Introns are removed before the RNA is translated.
D.
Bases are removed from the ends of the mRNA each time it is translated.
What happens during end product inhibition of the pathway shown below?
Substance W
enzyme I
Substance X
enzyme II
Substance Y
enzyme III
Substance Z
62.
A.
Enzyme I is inhibited by substance X.
B.
Enzyme I is inhibited by substance Z.
C.
Enzyme III is inhibited by substance W.
D.
Enzyme III is inhibited by substance Y.
What substance is moved into the thylakoids of the chloroplast using energy derived from light?
A.
Carbon dioxide (CO2 )
B.
Protons (H+)
C.
Glycerate 3-phosphate (GP)
D.
Adenosine triphosphate (ATP)
23
63.
What colours of light give the two peaks on the graph of the action spectrum of photosynthesis
shown below?
% absorption
wavelength of light
64.
A.
Red and infrared
B.
Green and red
C.
Blue and green
D.
Blue and red
The diagram shows part of a molecule produced by replication of DNA. What is the
significance of the shaded and the unshaded regions?
A.
The shaded parts are DNA and the unshaded parts are mRNA.
B.
The shaded parts contain adenine and thymine and the unshaded parts contain guanine
and cytosine.
C.
The shaded part is a codon and unshaded part is an anticodon.
D.
One of the parts has been newly synthesized and the other was part of a pre-existing DNA
molecule.
24
65.
66.
If mRNA has a codon CAU, what is the corresponding anticodon on the tRNA molecule?
A.
CAT
B.
GUA
C.
CAU
D.
GTA
Which graph shows the relationship between the substrate concentration and the rate of an
enzyme controlled reaction?
B.
Rate of
reaction
Rate of
reaction
A.
Substrate
concentration
Substrate
concentration
D.
C.
67.
68.
What are pyrimidines in DNA?
A.
Types of nucleotides
B.
Types of base pairs
C.
Types of sugars
D.
Types of bases
Which enzyme removes the RNA primer during replication?
A.
RNA primase
B.
DNA polymerase I
C.
DNA ligase
D.
Helicase
25
69.
Consider the metabolic pathway shown below.
1
2
3
4
V WXYZ
If there is end-product inhibition, which product would inhibit which enzyme?
70.
71.
Product
Enzyme
A.
X
4
B.
W
3
C.
W
2
D.
Z
1
What is the net production of ATP, per molecule of glucose during the fermentation of glucose
to lactate?
A.
36 molecules
B.
4 molecules
C.
2 molecules
D.
None
The diagram below summarizes the light-dependent reactions in photosynthesis. What is
occurring at X?
Electrons
X
Electrons
Light
Photosystem I
Light
Photosystem II
A.
ADP + phosphate  ATP
B.
NADP+NADPH + H+
C.
H2O  O2– + 2H+
D.
NADPH + H+  NADP+
26
72.
What is the first identifiable product of carbon dioxide fixation in photosynthesis?
A.
Ribulose bisphosphate (RuBP)
B.
Glycerate3-phosphate (GP)
C.
Triose phosphate (TP)
D.
Acetyl CoA
MC:
1.
B
20.
D
38.
D
56.
D
2.
D
21.
B
39.
A
57.
C
3.
B
22.
C
40.
D
58.
C
4.
D
23.
C
41.
A
59.
C
5.
C
24.
B
42.
A
60.
C
6.
A
25.
A
43.
C
61.
B
7.
C
26.
D
44.
A
62.
B
8.
B
27.
D
45.
A
63.
D
9.
C
28.
A
46.
A
64.
D
10.
C
29.
D
47.
A
65.
B
11.
A
30.
C
48.
D
66.
B
12.
B
31.
D
49.
B
67.
D
13.
C
32.
A
50.
B
68.
B
14.
A
33.
B
51.
C
69.
D
34.
B
52.
B
70.
C
35.
B
53.
A
71.
72.
A
B
36.
C
54.
C
37.
A
55.
C
15.
C
16.
D
17.
D
18.
C
19.
A
27