Download a. Define chromosome? Describe the structure, functions and their

B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
Section A
1. Multiple choice type questions (Tick √ the appropriate answer)
i) The chief role of nucleolus in a nucleus concerns …c) ribosomal synthesis
ii) Microtubule is involved in……………. b) Cell division
iii) A Eukaryotic cell without endoplasmic reticulum b) RBC of mammals
iv) Crossing over occurs during b) pachytene
v) Line Weaver equation state …c) y= mx +c
vi) Sulphur content of insulin is ….a) 3.4 %
vii) Steroids are example of a) Derived lipids
viii) When both the strand of DNA are cut at same position the resulting strand has.. (a) blunt end
ix) Genetic engineering is also known as (c) i & ii both
x) The only membrane bound enzyme in tricaboxylic acid cycle is (a) succinate dehydrogenase
Section B
Q2.Descriptive Type (Answer any four):
a. Define chromosome? Describe the structure, functions and their type chromosome.
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B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
Qb. Give an illustrated account of mitosis (with diagram). Compare and contrast mitosis and meiosis.
B Sc Zoology (F Sc Hon’s) Examination 2013
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LZC-201: Cell biology and Biochemistry
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
Qc. Derive the Michaelis Meten equation and compare it with Line weaver plot for Km and Vmax.
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
B Sc Zoology (F Sc Hon’s) Examination 2013
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LZC-201: Cell biology and Biochemistry
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
d. Give stepwise Embden-Meyerhof pathway showing degradation of glucose to pyruvic acid.
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
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Qe. Describe in detail about the structural polysaccharides with their function in animal system
Compound sugar yielding more than 10 molecules of monosaccharides which could be same or different.
Representing formula…. (C6 H 10 O5) x
1 (Same type of monosaccharides)
POLYSACCHARIDES .
2. HETROPOLYSACCHARIDES (Different type of monosaccharides)
Structural polysaccharides serve as rigidmechanical structure in plants and animals e g. cellulose, starch, chitin
CELLULOSE
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
Qf. Describe structure and function of different type of RNA.
THREE TYPES OF RNA
1. Messenger RNA Reads the DNA to see which amino acids are needed, contained by what quantity, and within what
order. 2. Transfer RNA bonds beside the needed amino acids and delivers them to theribosomes, where on earth
Ribosomal RNA assembles the amino acids into polypeptides, which will be assembled further into proteins.Helps in
transcription as … DNA needs stuff; mRNA takes the order; tRNA trucks the parts over to the factory, and rRNA
moderately assembles them and ships them off to be completed 2.Transfer RNA (tRNA) A class of RNA that has triplet
nucleotide sequence complementary to the triplet nucleotide coding sequences of messenger RNA (mRNA). The role of
tRNAs is to bond near amino acids and transfer them to the ribosomes, where on earth proteins are assembled according
to the genetic code carried bymRNA
2. Transfer RNA (tRNA) contains about 75 nucleotides, three of which are called anti-codons, and one amino acid. The
tRNA reads the code and carries the amino acid to be incorporated into the developing protein.There are at least 20
different tRNA's - one for each amino acid. The basic structure of a tRNA is shown in the left graphic. Part of the tRNA
doubles back upon itself to form several double helical sections. On one end, the amino acid, phenylalanine, is attached.
On the opposite end, a specific base triplet, called the anticodon, is used to actually "read" the codons on the mRNA.The
tRNA "reads" the mRNA codon by using its own anticodon. The actual "reading" is done by matching the base pairs
through hydrogen bonding following the base pairing principle. Each codon is "read" by various tRNA's until the
appropriate match of the anticodon with the codon occurs.
B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
tRNA Is An Adpator molecule that Couples Codons and Amino Acids
3. rRNA-
Ribosomes RNA, a molecular component of ribosomes, the cell's essential protein factory. Strictly speaking,
ribosomal RNA (rRNA) does not make proteins. It makes polypeptides (assemblies of amino acids) that go to build up
proteins.In the cytoplasm, ribsomal RNA (rRNA) and protein combine to form a nucleoprotein called a ribosome. The
ribosome serves as the site and carries the enzymes necessary for protein synthesis. In the graphic on the left, the
ribosome is shown as made from two sub units, 50S and 30 S. There are about equal parts rRNA and protein. The far left
graphic shows the complete ribosome with three tRNA attached.The ribosome attaches itself to m-RNA and provides the
stabilizing structure to hold all substances in position as the protein is synthesized. Several ribosomes may be attached to a
single RNA at any time. In upper right corner is the 30S sub unit with mRNA and tRNA attached.
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B Sc Zoology (F Sc Hon’s) Examination 2013
LZC-201: Cell biology and Biochemistry
Qg. Define nucleosome. Give the detail structure of nucleosome with the help of selonoid model of chromatin.
The nucleosomes give the DNA strand the appearance of a string of beads, and this arrangement of
DNA wrapped around histones serves to package the DNA efficiently and protected from enzymatic
degradation.
Nucleosome model provides the detail about the packaging of the chromosome
146 base pair of
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