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BBC811S - BIOINORGANIC AND BIOPHYSICAL CHEMISTRY - 2ND OPP - JULY 2022 |
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NAMIBIA UNIVERSITY
OF SCIENCE AND TECHNOLOGY
FACULTY OF HEALTH, APPLIED SCIENCES AND NATURAL RESOURCES
DEPARTMENT OF NATURAL AND APPLIED SCIENCES
QUALIFICATION: BACHELOR OF SCIENCE HONOURS
QUALIFICATION CODE: O8BOSH
LEVEL: 8
COURSE CODE: BBC8115
COURSE NAME: BIOINORGANIC AND BIOPHYSICAL
CHEMISTRY
SESSION: JULY 2022
DURATION: 3 HOURS
PAPER: THEORY
MARKS: 100
SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION QUESTION PAPER
EXAMINER(S) | DR. EUODIA HESS
MODERATOR: | DR. LIKIUS DANIEL
INSTRUCTIONS
Answer ALL the questions.
Write clearly and neatly.
Number the answers clearly
All written work must be done in blue or black ink and sketches can
be done in pencil
5. No books, notes and other additional aids are allowed
THIS QUESTION PAPER CONSISTS OF 4 PAGES (Including this front page, list of useful constants
and Periodic Table)
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SECTION A
[60]
QUESTION 1:
[10]
What are the biological roles/functions of the following metals:
a) Co
b) Cu
c) Na
d) Ca
e) K
QUESTION 2:
[10]
What are the donor atoms according to the hard soft acid base (HSAB) theory? Explain with
examples if they hard, soft or intermediate.
QUESTION 3:
[40]
3.1 In medicine the use of metal ions and their associated complexes is widespread. Among
Metal ions commonly used over the centuries were Hg** for treatment of syphilis, Mg?*
for intestinal disorders and Fe2*for anaemia. Today one of the leading anticancer drug is
cis-[Pt(NHs)2Cl.], cisplatin, which was first approved for use in 1978.
i) Against which type(s) of cancer is cisplatin effective?
(3)
ii) Draw the structure of cisplatin.
(2)
iii) How does cisplatin function as a anticancer drug?
(3)
iv) What are the disadvantages of using cisplatin as an anticancer drug?
(2)
3.2 Name three other platinum drugs that are utilized as an anticancer drug and for each drug
answer question i — iv for them as well.
(30)
SECTION B:
[40]
QUESTION 1:
[10]
The kinetics of CO, hydration catalysed by the enzyme carbonic anhydrase is as follows:
CO, + H,O0 «+ HCO3 + H*
The following initial reaction rates for the hydration reaction were obtained for an initial
enzyme concentration of 2.3 nM and temperature of 0.5 °C:
M s?
.78 x 105
.00 x 105
.33 x 105
.67 x 10°
CO.] (mM
.25
5
.0
0.0
QUESTION 2:
[10]
2.1 Obtain a balanced chemical equation and calculate the standard electrochemical potential
for reduction of Fe?* to Fe by Zn metal (Zn?*— Zn E° - 0.7618 V ; Fe?* > Fe E°=-0.037V). (5)
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2.2 The enzyme glutathione reductase replenishes the cell’s supply of GSH regenerating two
molecules of GSH from single molecule of oxidized gluthione (GSSH), using NADPH as a source
of two reducing equivalents. A typical cellular NADP*/NADPH ratio is 0.005, calculate the
equilibrium cellular concentration of GSSG at pH 7 and 25°C, if GSH concentration is 4 mM.
(GSSG + 2H* + 2e° > 2 GSH E° = -0.240 V; NADP* + H* + 2e° — NADPH E° = -0.339 V).
(5)
QUESTION 3:
[10]
For the hydrolysis of ATP, standard conditions do not prevail in the cellular environment. In the
Cell, typical concentrations of ATP, ADP and inorganic phosphate are Cate = 1850 LM, Capp =
138 uM, and cpi= 1.00 mM. Calculate the Gibbs energy of hydrolysis in the cellular environment,
assuming pH = 7 and T = 310 K.
QUESTION 4:
[10]
The enthalpy of melting ice at 1 bar is 6.007 kJ/mol; the density of water at 0 °C is 999.9 kg m3,
While that of ice is 915.0 kg m3. Assuming AV" and AHm'¥S°" are constant, determine the
freezing point of water at 100 bar.
END OF EXAMINATION
USEFUL CONSTANTS:
Gas constant, R = 8.3145 J -mol?: K?= 0.083145 dm?: bar: mol: K+= 0.08206 L atm mol?: K+
1Pa:m?=1kPal =1N-'m =15J
1 atm = 101 325 Pa = 760 mmHg = 760 torr
Faradays constant = 96,485 C/mol
Avogadro’s Number, Na = 6.022 x 1023 mol
Planck’s constant, h = 6.626 x 1034 Js
Speed of light, c = 2.998 x 108 ms?
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