1] All the following statements regarding "Protein choline acetyl transferase {ChAT} are true except :

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

Ans : A

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 :

1. No detectable citrulline
2. Elevated levels of arginine
3. Elevated levels of urea
4. No detectable ornithine

Ans : A

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

1. Oxidative phosphorylation occurs in mitochondria
2. Fatty acid synthesis occurs in mitochondria
3. Glycolysis occurs in the mitochondria
4. Ganglioside degeneration occurs in lysosomes

Ans : B {fatty acid synthesis occurs in cytosol}

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

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

Ans : D

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

1. p21
2. p27 Kip1
3. p53
4. p16

Ans : C

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

1. Di George's syndrome
2. Ataxia- telangiectasia
3. X- linked hypogamma globulimia
4. none of the above

Ans : A

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

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

Ans : B

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 ?

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

Ans : D

9] All the following are primary G1 cyclins EXCEPT :

1. Cyclin E
2. Cyclin D1
3. Cyclin B
4. Cyclin D2

Ans : C

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

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

Ans : D

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

1. A vegetarian diet
2. the administration of bile-acid sequestration resin
3. familial hypercholesterolemia
4. a long term high cholesterol diet .

Ans : D