Nucleic acids 1

Question 1

mRNA 🡆protein

this process is called?

Answer 1

Translation

Question 2

DNA 🡆 mRNA is called

Answer 2

Transcription

Question 3

INHIBITS:
⮞ purine biosynthesis
⮞ xanthine oxidase activity

Answer 3

allopurinol

Question 4

Cytarabrine is used for _____ therapy

Answer 4

cancer

Question 5

Azathioprene is used during _______ for supression of immunulogic rejection

Answer 5

organ transplantation

Question 6

Translation occurs in the _______ located in the cytoplasm

Answer 6

ribosomes

Question 7

In HIV, the enzyme _____ converts RNA genome to a viral DNA

Answer 7

Reverse transcriptase

Question 8

_____ units are called nucleotide

Answer 8

monomeric

Question 9

What are the major components of a nucleotide?

Answer 9

⮞ Phosphate group
⮞ sugar
⮞ nitrogenous base

Question 10

The ____ group in a nucleotide is the reason why it is negatively charged.

Answer 10

phosphate

Question 11

Nitrogenous base is linked to the _____ of sugar

Answer 11

Carbon 1’

Question 12

Phosphate group is linked to the _____ of sugar

Answer 12

Carbon 5’

Question 13

In what carbon is the difference between a deoxyribose and ribose?

Answer 13

carbon 2’

Question 14

____ is a more stable conformation than C3’-endo/A-form

Answer 14

C2’-endo/B-form

Question 15

Purines have 2 rings and 8 atoms. It’s bases are Guanine and Adenine. Are both statements correct?

Answer 15

NO, purines have 9 atoms.

Question 16

Pyrimidines have 6 atoms and 1 ring only. It’s bases are cytosine, uracil and thymine. Are both statements correct?

Answer 16

YES

Question 17

Under cellular pH conditions, phosphoric acid loses ______ to give a hydrogen phosphate ion

Answer 17

2 hydrogen atoms

Question 18

What is the term for the linkage of a phosphate group with a sugar?

Answer 18

phosphoester bond

Question 19

What are the components of the nucleoside?

Answer 19

base and sugar

Question 20

What is the term for the linkage of a sugar and a base?

Answer 20

glycosidic bond

Question 21

between the conformations of nucleosides, which is the most favored for its stability?

Answer 21

anti conformation

Question 22

Nucleotides have a ______ attached to the C5’ end

Answer 22

free phosphate group

Question 23

Nucleotide have a _______ attached to the C3’ end

Answer 23

free hydroxyl group

Question 24

What are the major stacking forces of bases in DNA?

Answer 24

⮞ Hydrophobic interaction

⮞ Van Der Waals Forces

Question 25

What is the significance of the major groove and the minor groove?

Answer 25

the site where transcription factors interact

Question 26

According to one of Chargaff’s Rules, the sum of the purine residues equals the

Answer 26

sum of pyrimidine residues

Question 27

According to Watson-Crick Base pairs,

Adenine - Thymine:

Answer 27

2 hydrogen bonds

Question 28

Defined by Watson-Crick B-form DNA from 1953,

DNA contained deoxyribonucleosides in _____ linkage

Answer 28

5’-3’ phosphodiester

Question 29

The A-form is a ________ double helix

Answer 29

Right-handed

Question 30

Z form DNA is a _______ helical rotation

Answer 30

left-handed

Question 31

What form of DNA is the most stable?

Answer 31

B form (Watson-Crick structure)

Question 32

According to Watson-Crick Base pairs,

Cytosine - Guanine:

Answer 32

3 hydrogen bonds