Structural Biochemistry 1 (BCHS3101)
BSc, Biochemistry - BCHS
Semester: First Semester
Level: 300
Year: 2018
1/2
REPUBLIC OF CAMEROON
Peace - Work - Fatherland
The UNIVERSITY OF
BAMENDA
P.O. BOX 39 Bambili
ntia8 Px Ik1113; ''''''
Course Code:_ 13CHS3101_ C
u
'- Title: __Strueturat Bioeh'eMistry I
Date: 28-02- 2018 _______________ HAW, ....... PBB07 &. 08 ........ Time; 11:00 - 14:00 ..
Instructions; Answer questions in ordering manner
and
,
da
not miss different, exercises
Exercise 1
(46 marks)
A) MCQ
(3
mrks)
1) Which out of the following amino acids carries a net positive charge at the physiological pH ?
a) Valine b) Leucine
c)
Isoleucine d) None of the above
2) All of the below mentioned amino acids can participate
in
hydrogen bonding except one —
a) Serine b) Cysteine c) Threonine d) Valine
3) The greatest buffering capacity at physiological pH
would be provided by a protein rich in
which
of the following amino acids? a) Serine b)Cysteine c) Alanine d) Histidine
4) Which out of the following is not a fibrous protein? a) Carbonic anhydrase b) Collagen
c) Fibrinogen d) Keratin
5) Which one of the following amino acids may be considered a hydrophobic amino acid at
physiological p H of 7.4? a) Isoleucine b) Arginine c) Aspartic acid d) Threonine
6) Which of the amino acids below is the uncharged derivative of an acidic amino acid?
a) Cystine b) Tyrosine c) Glutamine d) Serine
B)
During a practical of Biochemistry, Lionel, a year 2 student, accidentally forgot to label
clearly the prepared solutions, and it resulted in a mix up. Fortunately she remembered that there
was a tube containing KPA, Val, palm oil and starch solutions, respectively.
1) Classify the studied biomolecules (2 mrks)
2) Propose structure of the 1
st
two biomolecules (4 mrks)
3) Help Lionel identify the different solutions by completing the table below (16 mrks)
Biomolecule Specific
i
reagent(s)
Name of the
method
Specificity Name of the
color formed
KPA _
Val
Palm oil
Starch
4) Give the equation of titration of both molecules (KPA and Val) using the following pKas
pKαCOOH 2.2, pkβCOOH 3.9, pKαNH
2
19.2, pKH
2
12.48 (8 mrks)
5) Deduce their pl (3 mrks)
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6) In order to understand the effect of some physic-chemical factors on KPA and Val,
Lionel treated them as indicated in the table. Help him to
deduce any possible result
to
obtain (10 mrks).
UV radiation
10% CuSO4
Saturated
(NH
4
)
2
S0
4
BrCN
Strong
alkaline pH
KPA
Val
7) What additional simple test(s) could Lionel use to check nucleic acid in solution? (3
mrks)
Exercise 2
(24 marks)
1) You are the following sequence: 5'-UCCAAGCUAACG-3’
a) Justify the type of nucleic acid is it? (1 mrk)
b) What can its cellular role? (2 mrks)
c) Propose its retrotranscripted sequence (3 mrks)
2) Fill the table below (18 mrks):
Compound Main characteristics
Example
Function . Cellular location
Nucleotide
Nucleoside
Deoxynucleoside
tRNA
DNA
mRNA
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