BCHEM/III/EC/05 Student's Copy
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CBCS
3rd Semester
BIOCHEMISTRY
Paper BC-III
Enzymology and Metabolism—II
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 10
Tick the correct answer in the brackets provided 1×10=10
1. International Enzyme Commission classifies enzymes into
three classes
six classes
four classes
ten classes
2. The pH at which an enzyme has maximum activity is known as
isoelectric pH
optimum pH
low pH
high pH
/57 1 Contd.
3. A holoenzyme is
functional unit
apoenzyme
coenzyme
All of the above
4. In competitive enzyme activity inhibition
the structure of inhibitor generally resembles that of the
substrate
inhibitor decreases apparent Km
Km remains unaffective
inhibitor decreases Vmax without affecting Km
5. A ketogenic amino acid is
valine
cysteine
leucine
threonine
6. The enzymes of urea synthesis are found in
mitochondria only
cytosol only
both mitochondria and cytosol
nucleus
7. All of the following statements about the enzymic complex that carries out
the synthesis of ATP during oxidative phosphorylation are correct, except
it is located on the matrix side of the inner mitochondrial
membrane
it is inhibited by oligomycin
it can exhibit ATPase activity
it can bind molecular O2
8. Electron transport and phosphorylation can be uncoupled by compounds
that increase the permeability of the inner mitochondrial membrane to
electrons
protons
uncouplers
All of the above
BCHEM/III/EC/05/57 2 Contd.
9. Free ammonia is released during
oxidative deamination of glutamate
catabolism of purines
catabolism of pyrimidines
All of the above
10. Debranching enzyme is absent in
Cori's disease
Andersen's disease
von Gierke's disease
Hers disease
SECTION—B
Marks 15
Write short notes on the following 3×5=15
1. Activators
OR
Cofactors
2. Allosteric enzymes
OR
Isoenzymes
3. Albinism
OR
Alkaptonuria
4. Uncouplers
OR
Cellular respiration
5. Hyperglycemia
OR
Lipid malabosrption
BCHEM/III/EC/05/57 3 Contd.
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. What are enzymes? Briefly explain the units of enzyme activity. Add a note
on the formation of E-S complexes.
OR
Write brief notes on the following 5+5=10
Active site of enzyme
Transition state theory
2. Explain in detail the Michaelis-Menten equation for unisubstrate reactions.
Add a note on the significance of Km and Vmax. 6+4=10
OR
Write brief notes on the following 5+5=10
Reversible and irreversible enzyme inhibitions
Clinical importance of plasma lipase and alkaline phosphatase
3. Discuss in detail the biosynthesis of aromatic amino acid. 10
OR
Write brief notes on the following 5+5=10
Glycogenic and ketogenic amino acids
Urea cycle
4. Explain in brief the components of respiratory electron transfer chain. 10
OR
Write brief notes on the following 5+5=10
Oxidative phosphorylation
Inhibitors of oxidative phosphorylation
5. Explain in brief the degradation of purine nucleotides. Add a note on
salvage pathway for purines. 6+4=10
OR
Write brief notes on the following 5+5=10
Pyrimidine biosynthesis
Gout