Friday 16 June 2023 Morning Time allowed: 2 hours
Materials
For Examiner’s Use
For this paper you must have:
a ruler with millimetre measurements Questio Mark
a scientific calculator. n
1
Instructions 2
Use black ink or black ball-point pen. 3
Fill in the boxes at the top of this page.
4
Answer all questions.
You must answer the questions in the spaces provided. Do 5
not write outside the box around each page or on blank 6
pages. 7
If you need extra space for your answer(s), use the lined pages at
8
the end of this book. Write the question number against your
answer(s). 9
Show all your working. 10
Do all rough work in this book. Cross through any work you do
not want to be marked. TOTAL
Information
The marks for the questions are shown in brackets.
The maximum mark for this paper is 91.
pg. 1
,[Type text]
pg. 2
, 2
Do not write
outside the
Answer all questions in the spaces box
provided.
0 1 .1 A student used chromatography to separate the different photosynthetic
pigments in a chlorophyll solution. She had the following materials.
Chromatography
paper A ruler and
pencil Suitable
glassware
A solvent (solvent A)
2 cm3 of the chlorophyll solution
Describe how she could use these materials to separate the
photosynthetic pigments by chromatography.
[4 marks]
0 1 .2 Using solvent A, the student separated five pigments. She then repeated
her method using a different solvent, B. Using solvent B, she separated
six pigments.
Explain the difference between these results.
[2 marks]
6
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, 3
Do not write
outside the
0 2 .1 Glutamate is a neurotransmitter involved in the transmission of nerve box
impulses from pain receptors to the brain. Ziconotide is a drug that can
reduce severe, constant pain. Ziconotide blocks the calcium ion channels
at some of the synapses which use glutamate.
The transmission of glutamate at synapses is similar to that of
acetylcholine.
Explain how ziconotide reduces severe, constant pain.
[5 marks]
Ziconotide is a polypeptide and acts on synapses in the spinal cord.
Scientists investigated the effectiveness of ziconotide in reducing
severe, constant pain.
Ziconotide was injected into each patient’s cerebrospinal fluid that
bathes the brain and spinal cord. Patients recorded the intensity of their
pain using a statistically valid scale.
0 2
.2 Suggest two reasons why the patients had ziconotide injected into their
cerebrospinal fluid rather than taking a pill containing the drug.
[2 marks]
1
2
Question 2 continues on the next page
Turn over ►
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