Nucleic Acids

Question 1

N1 for all nucleic acids

Answer 1

Aspartate

Question 2

N3 &N9 of purine

Answer 2

GlutamiNe

Question 3

C4,C5,C6 in pyrimidine

Answer 3

Aspartate

Question 4

C6 of purine

and

C2 of pyrimidine

Answer 4

CO2

Question 5

C4,C5,N7 of purine

Answer 5

GlyCiNe

Question 6

N3 of pyrimidine

Answer 6

Glutamate

Question 7

C2 and C8 of purine

Answer 7

THF

Carbon donor

Question 8

Leading strand in eukaryote

Lagging strand in eukaryote

Answer 8

Epsilon polymerase

Delta polymerase

Question 9

Repair in eukaryote

Answer 9

Beta

, epsilon

Question 10

Mitochondrial strand

Answer 10

Gamma polymerase

Question 11

Deficiency of enzyme of pyrimidine salvage enzyme

Answer 11

OPRT
Orotic aciduria
Megaloblastic anaemia
Rx uridine

Question 12

Enzyme for salvage pathway

It’s deficiency ,complete and partial ,is

Answer 12

HGPRT
LESCH NEYHAN SYNDROME
Kelly Seegmiller syndrome

Question 13

Unwinding proteins

Answer 13

Helicase
Topoisomerase
SSB

Question 14

Proof reading for eukaryote

Answer 14

All DNA polymerases except alpha , beta

Question 15

Ribozymes having roles in splicing

Answer 15

snRNA U1 ,U2 ,,U4 ,U5 ,U6

Question 16

Ribozymes which cleaves tRNA

Answer 16

Ribonuclease P

Question 17

How many ATP &GTP are required for one aa to be added to the polypeptide chain

Answer 17

2ATP for aa activation RDS
1 GTP for aa entry at A site
1 GTP for translocation

Question 18

Only step in protein synthesis where proof reading occurs

Answer 18

1st step
Activation
Amino acyl tRNA synthetase

Question 19

CRISPR CAS 9 system

Answer 19

Causes double strand breaks
Against bacterial
Transferred to progeny

Question 20

Gene imprinting

Answer 20

Mechanism of gene inhibition when a CH group is added at C-G bond
Involving histones
Diseases : Prader Willi syndrome
Angelman syndrome

Question 21

Micro array

Answer 21

Multiple mutation
SNP
…

Does not detect monosomy, trisomy ,microdeletion

Slow ,
can’t be done in any phase

Question 22

FISH

Answer 22

Rapid
Detects microdeletion
Can be done in any phase
Tells gene location in chromosome

Question 23

Most of the nucleoside phosphates involved in biological function are

Answer 23

5’-nucleotides are more often seen, they are simply written without any prefix.

Question 24

dietary purines and pyrimidines are

Answer 24

neither converted to nucleotides nor incorporated into nucleic acids. They are directly catabolized

Question 25

De novo synthesis operates mainly in

Answer 25

The purine nucleotides are synthesized by most of the tissues. However the major site is the liver. This pathway operates in the cytoplasm.

Question 26

prototrophs.

Answer 26

Since the human being can synthesize the purine and pyrimidine bases de novo, they are said to be prototrophs