Biochemistry test

a) ChAT is an enzyme that is synthesized on ribosome's located in the nerve terminal of presynaptic neuron .
b) ChAT synthesizes ACh from the substrates acetyl coenzyme A { Acetyl COA } & choline.
c) ChAT exists on nerve terminals of both central & peripheral nervous system.
d) ChAT is responsible for the synthesis of the neurotransmitter acetyl choline before vestibular storage.

2) If a person has a genetic defect in the enzyme that produces N-acetyl glutamate , the most likely clinical finding would be Hyperammonemia with :

a) No detectable citrulline
b) Elevated levels of arginine
c) Elevated levels of urea
d) No detectable ornithine

3) All the following statements correctly pair a metabolic pathway with its appropriate sub cellular location except

a) Oxidative phosphorylation occurs in mitochondria
b) Fatty acid synthesis occurs in mitochondria
c) Glycolysis occurs in the mitochondria
d) Ganglioside degeneration occurs in lysosomes

4) All the following statements regarding CARNITINE DEFICIENCY is true except :

a) Some patients of this autosomal recessive disorder respond to oral carnitine therapy .
b) A diet restricted to short & medium chain fatty acids will prove useful
c) Pathological fatty deposition in muscles are frequently seen
d) A deletion mutation in the gene for "carnitine palmitoyl transferase "would result in an entirely different phenotype .

5) All the following are cyclic dependent kinase inhibitors EXCEPT :

a) p21
b) p27 Kip1
c) p53
d) p16

6) Which of the following congenital immunodeficiencies involves only a T- cell deficiency?

a) Di George's syndrome
b) Ataxia- telangiectasia
c) X- linked hypogamma globulimia
d) none of the above

7) Which of the following is true about the enzyme it describes ?

a) Aldolase cleaves a carbon - carbon bond to create a carboxyl group.
b) Hydrolase adds water to break a bond
c) Isomerase hydrolyzes ester linkages to form an acid & an alcohol
d) Dehydrogenases adds water to a carbon-carbon bond without breaking the bond, or conversely , removing water to create a double bond.

8) A 80 year old lady with 35 year h/o NIDDM is admitted to a hospital for mental status changes .An arterial blood gas revels a pH of 7.26 & her anion gap is 12.Which of the following statements correctly describes her metabolic acidosis due to renal failure ?

a) A large anion gap is indicative of better compensation.
b) The metabolic acidosis is caused by an excess production of ammonia in the tubular cells
c) The large anion gap indicates that her plasma bicarbonate level is elevated.
d) This patient has already passed the hyperchloremic phase of her acidosis

9) All the following are primary G1 cyclins EXCEPT

a) Cyclin E
b) Cyclin D1
c) Cyclin B
d) Cyclin D2

10)All the statements about G0 arrest are true except :

a) G0 is a specialized , non growing state of the cell cycle
b) The rate of protein synthesis is drastically reduced here.
c) The slow dividing cells can remain in G0 state for weeks or even years.
d) The cells in G0 phase have more cyclin dependent kinases & G1 cyclins than cells in G1.

11) Low level cellular HMG-COA reductase activity in humans is mostly due to :

a) A vegetarian diet
b) The administration of bile-acid sequestration resin
c) familial hypercholesterolemia
d) a long term high cholesterol diet .

12) Which one of the following pairs of lipids & related compounds exhibit opposite biological activities?

a) 5-HPETE & leukotriene D4
b) Cholic acid & Lithocholic acid
c) Thromboxane A2 & Prostocyclin [PGI2]
d) Acetone & beta- hydroxybutyrate

13) The cost in high energy phosphate bonds for the formation of 1 mole of glucose from pyruvate is :

a) 8moles of ATP
b) 6 moles of ATP
c) 4 moles of ATP
d) 2 moles of ATP

14) Which of the statements best charecterize glucose ?

a) It usually exits in furanose form
b) Its a ketose
c) It forms part of the disaccharide sucrose
d) It is oxidized to form sorbitol

15) Which of the following enzymes catalyze reactions in the biosynthesis of both catecholamines & Indoleamines (serotonin)

a) Dopamine beta - hydroxylase
b) Phenyl ethanolamine N-methyl transferase
c) Aromatic amino acid decarboxylase
d) Tryptophan hydroxylase

16) Which of the statements about protein structure is true ?

a) The extended beta-configuration is not found in globular proteins
b) The stability of the alpha helix is mainly due to hydrophobic interactions
c) Globular proteins tend to fold into configurations that keep hydrophobic side chains in the interior of the molecule
d) The primary structure of a peptide does not influence the formation of native 3 dimensional configuration

17) Ammonium ion is released by:

a) Arginase
b) Glutamate dehydrogenises
c) Glutaminase
d) All of the above

18) Collagen synthesis, hydroxyproline is converted to:

a) Prolene
b) Lysine
c) Hydroxy lysine
d) None of the above

19) Competitive inhibition is characterized by:

a) Increased Km and V Max is same
b) increased Vmax and Km remains constant
c) increased Km and increased Vmax
d) Decreased Km and increased Vmax

20) Absorption of vitamin D in intestine is helped by:

a) Calcium
b) Potassium
c) Magnesin
d) Iron

Quiz script provided by
The E-Doctor

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