Download 2004-05

CHE-09
Assignments 1 and 2
CHE-09
Biochemistry
Elective Course in Chemistry and Life Sciences
School of Sciences
Indira Gandhi National Open University
New Delhi-110 068
2004
Dear students,
We hope you are familiar with the system of evaluation to be followed for the Bachelor’s Degree
Programme. At this stage you may probably like to re-read the section on assignments in the Programme
Guide for Elective courses that we sent you after your enrolment. A weightage of 30 per cent, as you are
aware, has been earmarked for continuous evaluation which would consist of two tutor-marked
assignments (TMA) for this course. Both these assignments are in this booklet.
Instructions for Formating Your Assignments
Before attempting the assignment, please read the following instructions carefully.
1. On top of the first page of each TMA answer sheet, please write the details exactly in the following
format:
Enrolment No : .........................……………
Name : ........................…………….
Address : ........................…………….
Course Code : ........................……………
…...………………………..
Course Title
…………………………….
: .......................…………….
Assignment No : ......................…………….
Study Centre : ...........................................
Date
: ………...........................…..
(Name and Code)
PLEASE FOLLOW THE ABOVE FORMAT STRICTLY TO FACILITATE EVALUATION
AND TO AVOID DELAY.
2. Use only foolscap size writing paper (but not of very thin variety) for writing your answers.
3. Leave 4cm margin on the left, top and bottom of your answer sheet.
4. Your answers should be precise.
5. While solving problems, clearly indicate the question number along with the part being solved.
6. These assignments are to be submitted as follows:


First assignment to be submitted to the Study Centre Coordinator within 6 weeks of receiving
this booklet.
Second assignment to be submitted to the Study Centre Coordinator within 12 weeks of
receiving this booklet.
Answer sheets received after the due date shall not be accepted.
We strongly suggest that you should retain a copy of your assignments.
Wishing you all good luck.
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Assignment – 01
Tutor Marked Assignment
Biochemistry
Elective Course in Chemistry and Life Sciences
Course Code: CHE-09
Assignment Code: CHE-09/TMA-1/2004
Maximum Marks: 100
Answer all the questions given below.
1.
a)
b)
Describe the biochemical composition of a living organism.
Explain the structure and functions of mitochondria.
(5)
(5)
2.
a)
Why do monosaccharides form cyclic structure? Draw the structures of open chain and
cyclic forms of glucose.
Taking an example of D-glucose explain the term mutarotation.
Write the reaction of glucose with i) strong mineral acid and ii) Benedict’s solution.
(5)
Write structures for disaccharides in which glucose units are linked together in the
following ways.
i)  - 1,4
ii)  - 1,4
iii)  - 1,6
iv)  - 1,6
What is the principal structural difference between amylose and cellulose?
What is the difference between a fat and a fatty acid?
Give definition of iodine number.
(4)
Describe the structural differences between a triacylglycerol and a phospholipid. Give
one example in each case.
What is the name of the fatty acid formed in the route from compound lipid to
prostaglandins ?
What similarities in composition are there in the four DNA nucleotides ?
(4)
i) In what way the process of transcription similar to that of replication ?
ii) What result is obtained from each process ?
What is the functional role of tRNA and rRNA ? Where are these RNAs found in cell?
(4)
Describe the isoelectric point. With the help of an example explain the utility of this
property of amino acids and how is it useful in maintaining pH in human systems.
How are the peptides named ? Write the structure of a tripeptide of your choice and
write its full and abbreviated name.
(5)
Explain the stereochemistry of peptide bond. What do the  and  angles signify in
peptides ?
Why are the amino acids forming polypeptide chains called residues ?
What type of bonds or interactions stabilise a protein
i) consisting of amino acids with aliphatic side chain ?
ii) consisting of cysteine residues ?
iii) consisting of lysine and glutamic acid residues ?
(5)
b)
c)
3.
a)
b)
c)
d)
4.
a)
b)
c)
5.
a)
b)
6.
a)
b)
7.
a)
b)
c)
3
(3)
(2)
(2)
(2)
(2)
(2)
(4)
(6)
(5)
(2)
(3)
8.
a)
b)
9.
a)
b)
c)
10.
a)
b)
What is meant by active site of an enzyme ? How do the binding groups and catalytic
groups of an active site differ from each other ?
What are the various types of specificities exhibited by enzymes? Illustrate your answer
with an example for each.
(4)
What is the basic principle involved in the mechanism of enzyme action in biological
reactions ?
What is meant by the optimal pH and temperature in enzymatic reactions? How are
these related to the catalytic efficiency ?
What is the relationship between Vmax and Km ? Explain in brief.
(4)
Give the role of following vitamins in biochemical reactions. Explain with the help of
an example.
i)
Thiamine
ii)
Pyridoxine
iii)
Riboflavin
Differentiate between macrominerals and trace elements. Which element is a part of
vitamin B12 and coenzyme A? Give their biological roles.
(6)
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(6)
(4)
(2)
(4)
Assignment – 02
Tutor Marked Assignment
Biochemistry
Elective Course in Chemistry and Life Sciences
Course Code: CHE-09
Assignment Code: CHE-09/TMA-2/2004
Maximum Marks: 100
Answer all the questions given below.
1.
a)
b)
2.
a)
b)
c)
3.
a)
b)
c)
4.
a)
b)
5.
a)
b)
c)
Define standard free energy change for biochemical reactions and give the symbol used
for it. How is it different from free energy change ?
What is the significance of oxidative phosphorylation? Illustrate with the help of two
examples.
(4)
Explain what is meant by the convergent and divergent nature of catabolism and
anabolism respectively.
Differentiate between homolactic and alcoholic fermentation. Illustrate with the help
of an example.
Is the conversion of pyruvate into phosphoenolpyruvate thermodynamically feasible?
Give reason for your answer.
(3)
How is the enzyme pyruvate dehydrogenase complex different from other enzymes ?
How does it function in the conversion of pyruvate to acetyl- CoA?
What is the role of FAD and NAD+ during the conversion of succinate to
oxaloacetate in Kreb’s cycle ?
How is the conversion of fatty acid to acyl - CoA accomplished thermodynamically?
(6)
Explain the following terms:
(i)
Constitutive and induced enzymes
(ii)
Metabolic regulation
(iii) Product inhibition
Explain the role of uncouplers in electron transport chain or oxidative phosphorylation.
Illustrate your answer with the help of an example.
(6)
(3)
(4)
(2)
(2)
(6)
(4)
Why chloroplasts happen to be the seat of photosynthesis ?
What is the difference between the electron transport reactions of mitochondria and
the ones which take place in photosynthetic process ?
What are the various modes by which the excited molecule loses energy when it comes
back to the ground state during photosynthesis?
(2)
(3)
Give a brief account of the steps involved in polypeptide chain formation.
How is protein biosynthesis inhibited by antibiotics? Explain by taking a suitable
example.
(6)
(4)
6.
a)
b)
7.
Explain the following terms.
a)
Termination codons
b)
Lac operon
c)
Chemical carcinogens
d)
Immobilised enzymes
(5)
(2½ 4)
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8.
a)
b)
How is gene cloning carried out for the production of hormones ? Explain by taking a
suitable example.
What is difference between immunity and hypersensitivity?
(5)
(5)
(2)
(3)
(5)
9.
a)
b)
c)
Discuss briefly the experiment of Griffith and Avery.
What are the similarities between DNA replication and RNA transcription?
Fill in the blanks in the following:
i)
…………is involved in DNA replication.
ii)
………types of RNAs are found in the cell.
iii)
Exonuclease activity is not present in…………..
10.
a)
What are the factors that effect the immune response ?
(5)
Discuss them briefly.
Explain the term antibody.
(2)
Fill in the blanks in the following.
(3)
i)
………are produced by plasma cell.
ii)
Stem cells arise in …………..
iii)
Heptens are small molecules which serve antigens when combined with ………
b)
c)
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