BIOCHEMISTRY

Question 1

Exacerbation of porphyria by barbiturates ?

Answer 1

De repression or induction of Ala synthase

Question 2

Tangier disease is ?

Answer 2

Autosomal recessive
Mutation in abc 1
Reduced triglyceride increased hdl
No treatment

Question 3

Total atp generated per turn of the transaction cycle ?

Answer 3

10

Question 4

Value of gas constant r

Answer 4

1.98 kcal/mol or 8.31/joules

Question 5

Nitogenous base with amino group on 6th carbon ?

Answer 5

Adenine
Guanine - 2nd
Cytosine - 4th
Methyl on thiamine at 5th

Question 6

Denovo synthesis doesn’t take place in ?

Answer 6

Brain
Bone marrow
Erythrocytes
Leucocytes

Question 7

Molecules which contribute to the synthesis of purine ring?

Answer 7

Aspartate
Glycine** - not involved in pyrimidine synthesis
Glutamine
CO2

Question 8

What is the rate limiting step of denovo purine synthesis?

Answer 8

conversion of5- phosphoribosyl-1- pyrophosphate(PRPP) to phosphoribosylamine(PRA) by PRPP Glutamyl amidotransferase

First intermediate - 5-phosphoribosyl-1-pyrophosphate(PRPP)
Rate limiting enzyme- PRPP Glutamyl amidotransferase. —- activated by PRPP and glutamine
Inhibited by - AMP and GMP

Question 9

The parent purine nucleotide made from denovo purine synthesis is?

Answer 9

Inosine monophosphate(IMP)

Question 10

How is the rate limiting enzyme in denovo purine synthesis regulated ?

Answer 10

Inhibited by purine nucleotides AMP and GMP and activated by concentration of glutamine

Question 11

Purely ketogenic amino acid ?

Answer 11

Leucine

Question 12

Purely ketogenic aa ?

Answer 12

Leucine

Question 13

Example of natural uncoupler ?

Answer 13

Thermogenin