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BBC811S - BIOINORGANIC AND BIOPHYSICAL CHEMISTRY - 1ST OPP - JUNE 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: O08BOSH
LEVEL: 8
COURSE CODE: BBC8115
COURSE NAME: BIOINORGANIC AND BIOPHYSICAL
CHEMISTRY
SESSION: JUNE 2022
DURATION: 3 HOURS
PAPER: THEORY
MARKS: 100
FIRST OPPORTUNITY EXAMINATION QUESTION PAPER
EXAMINER(S) | DR. EUODIA HESS
MopERATOR: | PR. 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,
Periodic Table)
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SECTION A
[50]
QUESTION 1:
[12]
Give a brief account for the following techniques used to study metals in biology:
a) Electron Paramagnetic Resonance (EPR) Spectroscopy.
(4)
b) NMR spectroscopy.
(4)
c) X-ray Diffraction
(4)
QUESTION 2:
[10]
a) Why is chelation important in medicine?
(4)
b) Why are corrins and pophyrins regarded as an important class of natural chelator molecules? (6)
QUESTION 3:
[16]
a) Which of the 20 amino acids are potential metal ligands?
(10)
b) Which of the low molecular weight inorganic anions bind to Fe** in proteins?
(2)
c) Which metals are inserted into the tetrapyrrole nucleus of corrins and porphyrins to form
vitamin Biz and other cobalamine cofactors, haem, chlorophyll and coenzyme Fa3o0
respectively?
(4)
QUESTION 4:
[12]
Describe the function and variety of siderophores.
SECTION B:
[50]
QUESTION 1:
[17]
1.1) Nicotine adenine dinucleotide (NAD) is a cellular redox reagent that is involved in redox
chemistry throughout respiratory system. The reduced form of NAD is NADH and oxidised form
is NAD*. An electrochemical cell is constructed using a half-cell for which the reduction is given:
NAD* + H*+ 2e — NADH
F°=-0.105V
which combined with the half-cells for which the reduction reaction is given by:
a) CO + H*2 + 2e° — HCOO-
F°=-0.105V
b) O+22H* + 2e°> H202
F°=0.69V
Write the overall reaction for the cells in the direction of spontaneous change. Is the NAD
reduced or oxidised in spontaneous reactions?
(9)
1.2) You are given the following reduction reactions and E® values at pH = 7.
CH3COO™ (aq) + 3H* (aq) + 2e° > CH3CHO (aq) + H20
F° =-0.581 V
CH3CHO (aq) + 2H* (aq) + 2e° > CH3CH20H (aq)
f° =-0.197 V
Where E° indicates the biological state. Calculate E* for the half-cell reaction:
CH3COO: (aq) + SH* (aq) + 4e° — CH3CH20H (aq) + H20 (I)
(8)
Page 2 of 4
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QUESTION 2:
[15]
The normal boiling temperature of benzene is 353.24 K, vapor pressure of liquid benzene is
1.00 x 104 Pa at 20 °C. The enthalpy of fusion is 9.95 kJ mol? and vapor pressure of solid
benzene is 88.0 Pa at -44.3 °C. Calculate the following:
a) AHm’??
(3)
b) ASm¥@?
(3)
c) Tripple point Temperature and Pressure
(9)
QUESTION 3:
[20]
a) In the cell, typical concentration of ATP, ADP and inorganic phosphate are Cate = 1850 uM,
Capp = 138 uM and cp = 1.00 mM. Calculate the Gibbs energy of hydrolysis in the cellular
environment, assuming pH = 7 and T = 310K.
(10)
b) The distributions of sodium and potassium ions inside and outside the cell membrane are
cN@t =1.4x109M, cXt = 5.0 x 103 M, cN@t= 1.00 x 102 M and cj,*= 1.00 x 107M.
Calculate the total free energy change involved in transporting 3 mol of sodium ion out of the
cell and 2 mol of potassium into cell at T = 310 K. Assume a potential difference of 0.070 V. (10)
END OF EXAMINATION
USEFUL CONSTANTS:
Gas constant, R = 8.3145 J -mol?: K?= 0.083145 dm?: bar: molt: K?= 0.08206 L atm mol?: K+
1Pa:m?=1kPa.l =1N'm =1J
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 104 Js
Speed of light, c = 2.998 x 108 ms+
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