DNA transcription and translation

Question 1

Fs[The interconversion of heterochromatin to euchromatin is called _____

and vice versa

Answer 1

Chromatin remodeling

by acetylation majorly

Question 2

RNA Polymerase 1 synthesizes

Answer 2

28S
18S
5.8S rRna

Question 3

RNA Polymerase 2 synthesizes

Answer 3

snRNA
miRNA
mRNA
snoRNA

Question 4

Where is the TATA sequence found

Answer 4

25 nucleotides upstream of transcription starting site

Question 5

TATA sequence is also called as

Answer 5

Hognes Box

Question 6

CAAT box is found

Answer 6

75-80 nucleotides upstream

Question 7

in which kind of sequence is TATA box not present {constitutive/non constitutive}

Answer 7

Constitutive

GC rich sequence is present instead

Question 8

How do transcription factors bind DNA

Answer 8

Helix-loop-helix
Zinc fingers
leucine zippers

Question 9

Promotes are called _____ binding factors {cis/trans}

Answer 9

Cis

Transcription factors are calles trans

Question 10

Function of TFIID

Answer 10

recognized and binds the TATA box

Question 11

Function of TFIIF

Answer 11

Brings polymerase to promoter

Question 12

Function of TFIIH

Answer 12

Melts the DNA and phosphorylates polymerase to promoter

Question 13

What is the function of coactivators

Answer 13

Chromatin remodeling

Question 14

Inhibitor of RNA polymerase II

Answer 14

Alpha amanitin

binds tightly with RNA pol II and causes dysentry and hepatotoxicity

Question 15

Where does rRNA synthesis and processing occur

Answer 15

Nucleolus

Question 16

Post transcriptional modifications for tRNA

Answer 16

(i) Removal of intron from anticodon loop
(ii) Addition of CCA to 3’ end
(iii) Production of unusual bases (hydrouracil, pseudouracil, methylation of bases)

i- nuclease ii- nucleotidyltransferase

Question 17

Steps involved in processing of mRNA

Answer 17

Capping
Polyadenylation
Splicing

Question 18

Enzyme required in capping

Answer 18

Guanylyltransferase

Question 19

Site for capping

Answer 19

cytosol

Question 20

Source of methyl group in capping

Answer 20

S adenosyl methionine

Question 21

Role of capping

Answer 21

Stabilize mRNA
initiation of translation

Question 22

Enzyme in tailing

Answer 22

Polyadenylate polymerase

Question 23

What is the polyadenylation signal sequence

Answer 23

AAUAA

found near 3’ end

Question 24

Function of tailing

Answer 24

Stabilize mRNA
facilitate its exit from nucleus
Aids in translation

Question 25

What happens to polyA tail upon entering the cytosol

Answer 25

It shortens

Question 26

Name the molecular complex which causes splicing

Answer 26

Spliceosome

Question 27

which primary transcript contains no introns

Answer 27

Transcripts from histone genes

Question 28

Name an autoimmune condition which result from individual antibodies against their own nuclear proteins like snRNPs

Answer 28

Systematic Lupus Erythromatosus | Anti U1 snRNP (also with mixed CT disease and other rheumatic dis )

Question 29

Name a disease which can happen due to mutation in the process of splicing

Answer 29

Beta Thalassemia

Question 30

What are the components required for translation

Answer 30

Amino Acid tRNA Amino acyl tRNA synthetase mRNA Ribosomes Protein factors ATP GTP

Question 31

Wobble hypothesis

Answer 31

The mechanism by which tRNA can recognize more than one codon for a specific amino acid

Question 32

Basis/Why does wobble occur

Answer 32

base at 5' end of anticodon is not as spatially define as those at 3' end

Question 33

where does mRNA quality processing occurs

Answer 33

cytoplasmic processing bodies

Question 34

Name the enzymes present in P bodies

Answer 34

Exonuclease Decapping microRNA

Question 35

mutation in what sequence leads to early degradation prior to translation

Answer 35

AAUAA

Question 35

what is the initiation site in most eukaryotic mRNA

Answer 35

Kozak sequence

Question 36

mutation in which sequence leads to impairment in initiation of translation

Answer 36

Kozak sequence

Question 37

in transcription which enzyme opens DNA at promoter site

Answer 37

RNA polymerase 2

Question 38

Which drug inhibits RNA polymerase in both pro and eu

Answer 38

Dactinomycin

Question 39

Which drug inhibits DNA dependent RNA polymerase in pro

Answer 39

Rifamycins | rifampicin and rifabutin

Question 40

What disease can mutation in snRNP cause

Answer 40

Floppy baby syndrome

Question 41

Floppy baby syndrome

Answer 41

Dec in SMN prot ----> effected snRNP assembly ---> congenital degeneration of ant horn of spinal cord ----> symmetric weakness | ant horn - corticospinal tract

Question 42

What does spliceosome consist of

Answer 42

snRNP and snRNA bound to proteins like Smith proteins

Question 43

role of arms in tRNA

Answer 43

T- tethers tRNA to ribosome D- Detection of tRNA by amino acyl tRNA synthetase

Question 44

What does a mischarges tRNA do

Answer 44

reads usual codon but inserts wrong amino acid

Question 45

_______kinases are regulatory proteins that regulate the transition to the S phase of the cell cycle and whose concentrations remain constant.

Answer 45

Cyclin dependent

Question 46

are regulatory proteins that regulate the transition to the S phase of the cell cycle and whose concentrations increase and decrease with the cell cycle.

Answer 46

Cyclin

Question 47

Most cells contain a checkpoint at the ____ phase of the cell cycle, often termed the restriction point.

Answer 47

G1

Question 48

A ______hybrid is a small segment where messenger RNA is still hydrogen-bonded to template DNA during the elongation phase of DNA transcription.

Answer 48

DNA-RNA

Question 49

The ______phase promoting factor is a protein complex that is required to allow the cell to move from the G2 phase to the M phase.

Answer 49

M

Question 50

What do eIF identify

Answer 50

5' cap help to assemble 40S ribosome unit with initiator tRNA

Question 51

ATP is required for

Answer 51

tRNA activation

Question 52

GTP is required for

Answer 52

tRNA translocation

Question 53

Synthesis occurs from _ terminus to _ terminus (N/C)

Answer 53

n to c

Question 54

Which enzyme catalyzes peptide bond formation

Answer 54

ribozyme

Question 55

______ factors are target of bacterial toxins | Diphtheria; Pseudomonas

Answer 55

Elongation

Question 56

Which sequence aligns ribosome with start codon in pro | identified by 16S ribosome

Answer 56

Shine Dalgarno sequence

Question 57

Name 2 major post translational modifications

Answer 57

Trimming Covalent alteration

Question 58

Trimming

Answer 58

Removal of n or c terminal propeptides from zymogen

Question 59

Give example of covalent alterations

Answer 59

Phosphorylation Hydroxylation Glycosylation Methylation Acetylation Ubiquitation

Question 60

In yeast which protein is constitutively expressed

Answer 60

HSP60

Question 61

What leads to increase in expression of chaperone proteins

Answer 61

high temp acidic pH hypoxia | to prevent denaturation or misfolding of protein

Question 62

Which factors recognizes stop codons

Answer 62

Eukaryotic releasing factors

Question 63

miRNA binds to which part of the mRNA to inhibit translation?

Answer 63

3' UTR region