HL, SL NUCLEIC ACIDS - PROTEINS REVIEW SHEET
1.
(a)
Explain the significance of secondary structure to the structure of a protein.
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(3)
(b)
State the name of a enzyme that digests protein.
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(1)
(c)
Outline the difference between globular protein and fibrous protein
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(2)
(Total 6 marks)
2.
State a role for each of two different named enzymes in DNA replication.
(Total 4 marks)
3. The structure of the DNA double helix was described by Watson and Crick in 1953.
Explain the structure of the DNA double helix, including its subunits and the way in
which they are bonded together.
(Total 8 marks)
4.
Compare DNA transcription with translation.
(Total 4 marks)
5.
Distinguish between the structure of DNA and RNA.
DNA
RNA
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(Total 3 marks)
6.
(a)
State two functions of proteins with a named example of each.
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2 marks
7.
Living organisms use DNA as their genetic material. Explain how DNA is replicated
within the cells of living organisms.
(Total 8 marks)
8.
Describe the genetic code.
9.
A DNA has AAT AGC GAG TTA nucleotides.
a. Write the nucleotide sequence of the complementary strand. ...........................................
b. Write the nucleotide sequence of the mRNA which is transcribed from above DNA.
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c. Label the genetic codes and codons.
d. Write the anticodons that recognize the mRNA in the question 9 b.
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10.
The enzyme aspartate carbomyltransferase (ACTase) is a key regulatory enzyme in
nucleotide metabolism in bacteria. The activity of this enzyme was studied in the
bacterium Helicobacter pylori, an important human pathogen. ACTase activity and
the growth of H. pylori were measured at different concentrations of carbomoyl
aspartate (CAA), the end product of the reaction catalysed by ACTase.
100
100
75
75
ACTase activity / 50
% of control
50
Key:
ACTase activity
H. pylori growth
25
Growth /
% of control
25
0
0
0
10
20
30
40
50
60
Concentration of carbamoyl aspartate / mmol dm–3
[Source: Burns, et al, Biological Procedures Online, (1998), http://www.biologicalprocedures.com]
(a)
(i)
State the growth of H. pylori at a CAA concentration of 30 mmol dm–3.
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(1)
(ii)
Calculate the change in ACTase activity between CAA concentrations
of 20 and 40 mmol dm–3.
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(1)
(b)
Compare the effect of increasing CAA concentration on the growth of H.
pylori and ACTase activity.
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(2)
(c)
Explain the effect of CAA on ACTase activity.
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(2)
(d)
Suggest a direct medical application of this information.
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(1)
(Total 7 marks)