DNA transcription

Question 1

first suggestion that RNA
is derived from the transcription of DNA

Answer 1

Elliot Volkin and Lazarus Astrachan (1956)-

Question 2

the base composition after infection was very similar
to the base composition in the T2 DNA,

Answer 2

except that the RNA
contained uracil instead of thymine.

Question 3

found that proteins
are synthesized on ribosomes.

Answer 3

Matthew Meselson and François Jacob (1960)-

Question 4

proposed that a certain
type of RNA acts as a genetic messenger (from the DNA to the
ribosome) to provide the information for protein synthesis.

Answer 4

François Jacob and Jacques Monod (1961)-

Question 5

directs the synthesis of particular polypeptides.

Answer 5

messenger RNA
(mRNA),

Question 6

Synthesis of RNA using DNA as a template

Answer 6

DNA TRANSCRIPTION

Question 7

No primer needed, no proofreading activity

Answer 7

DNA TRANSCRIPTION

Question 8

In eukaryotes, the polymerases synthesize specific RNA molecules:

Answer 8

• Pol I: rRNA
• Pol II: mRNA, lncRNA, miRNA, SnRNA
• Pol III: tRNA, 5S rRNA

Question 9

DNA TRANSCRIPTION Enzyme:

Answer 9

DNA-dependent RNA polymerase

Question 10

the overall process by which the information within a
gene is used to produce a functional product, such as a polypeptide.

Answer 10

Gene expression-

Question 11

is the first step in gene expression

Answer 11

Transcription

Question 12

provides a site for beginning transcription

Answer 12

Promoter-

Question 13

specifies the end of transcription

Answer 13

Terminator-

Question 14

to occur
within a defined location.

Answer 14

RNA synthesis

Question 15

• type of DNA sequence that gets its name from the idea that it
  “promotes” gene expression.

Answer 15

Promoter

Question 16

directs the exact location for the initiation of
transcription.

Answer 16

promoter

Question 17

The bases in a promoter sequence are numbered in relation to the

Answer 17

transcriptional start site

Question 18

most of the ____ is labeled with negative numbers

Answer 18

promoter

Question 19

• The sequence in the top DNA strand at the −35 site is

and

the one at the −10 site is

,

Answer 19

5′–TTGACA–3′

5′–TATAAT–3′.

Question 20

TATAAT sequence is called the ____
who initially discovered it in 1975.

Answer 20

Pribnow box after David Pribnow,

Question 21

___is complementary to the
template strand of DNA.

Answer 21

RNA transcript

Question 22

opposite strand of DNA is the ___

Answer 22

nontemplate strand.

Question 23

is also called the
coding strand, or sense strand, because its sequence is the same as
the transcribed mRNA

Answer 23

nontemplate strand

Question 24

is also called the non-coding strand, or antisense strand.

Answer 24

template strand

Question 25

controls the rate of transcription.

Answer 25

Transcription factors-

Question 26

complementary to a sequence in ribosomal RNA.

Answer 26

Ribosome-binding site (the Shine-Dalgarno sequence)

Question 27

read as groups of three nucleotides,

Answer 27

Codons-

Question 28

which is very close to the ribosome-binding site, is the start codon.

Answer 28

first codon,

Question 29

signals the end of translation.

Answer 29

stop codon

Question 30

Transcription occurs in three stages:

Answer 30

* Initiation * Elongation * Termination

Question 31

the enzyme that interact with the DNA sequences and synthesizes RNA.

Answer 31

RNA polymerase-

Question 32

Is a recognition step identifies the starting site for transcription when the DNA is in the form of a double helix.

Answer 32

Initiation stage

Question 33

the open promoter complex, or the open complex.

Answer 33

Elongation stage

Question 34

RNA polymerase and the newly made RNA transcript to dissociate from the DNA.

Answer 34

Termination stage

Question 35

eukaryotes : * TATA or Hogness box, about –25 bp * CAAT box, about –70 to 80 bp prokaryotes: * –35 sequence (TTGACA) * Pribnow box (TATAAT), about –10 bp

Answer 35

eukaryotes : * TATA or Hogness box, about –25 bp * CAAT box, about –70 to 80 bp prokaryotes: * –35 sequence (TTGACA) * Pribnow box (TATAAT), about –10 bp

Question 36

In prokaryotes, the core enzyme is composed of five subunits, ____.

Answer 36

α2ββ′ω

Question 37

important in the proper assembly of the holoenzyme and in the process of binding to DNA.

Answer 37

Two α subunits

Question 38

needed for binding to the DNA, and they carry out the catalytic synthesis of RNA.

Answer 38

β and β′ subunits-

Question 39

important for the proper assembly of the core enzyme.

Answer 39

ω (omega) subunit-

Question 40

The ___ is required to initiate transcription.

Answer 40

holoenzyme

Question 41

- primary role is to recognize the promoter.

Answer 41

sigma σ factor

Question 42

is a structure contained in a σ-factor(sigma)

Answer 42

Helix-turn-helix motif-

Question 43

within the protein fit into the major groove of the DNA

Answer 43

Alpha (α) helices

Question 44

* Local unwinding of the DNA continues in the 3’to 5’ direction * RNA is synthesized in a 5′ to 3′ direction using nucleoside triphosphates as precursors, releasing pyrophosphate each time

Answer 44

STEP 2: ELONGATION

Question 45

is made during the elongation stage.

Answer 45

RNA transcript

Question 46

the open complex formed by the action of, RNA polymerase is approximately __ bp long.

Answer 46

17

Question 47

On average, the rate of RNA synthesis is about ___ nucleotides per second.

Answer 47

43

Question 48

always connects nucleotides in the 5′ to 3′ direction.

Answer 48

RNA polymerase

Question 49

requires formation of a hairpin loop requires ρ protein to release RNA from DNA

Answer 49

* ρ-independent: * ρ-dependent:

Question 50

Elongation of RNA continues until a termination signal is reached

Answer 50

STEP 3: TERMINATION

Question 51

short RNA-DNA hybrid region is forced to separate,

Answer 51

Termination

Question 52

an RNA-binding protein responsible for terminating transcription, in a mechanism called

Answer 52

ρ (rho)- ρ-dependent termination.

Question 53

does not require the involvement of the ρ protein

Answer 53

ρ-independent termination.

Question 54

a site in the DNA encodes a sequence in the RNA that acts as a recognition site for the binding of the ρ protein

Answer 54

Rut site (for rho utilization site)-

Question 55

binds to the RNA and moves in the direction of RNA polymerase.

Answer 55

ρ protein

Question 56

* Does not require the ρ protein * One sequence promotes the formation of a stem-loop. * The second sequence, which is downstream from the stem-loop, is a uracil-rich sequence located at the 3′ end of the RNA.

Answer 56

ρ-INDEPENDENT TERMINATION (2 components)

Question 57

___ are removed and ___ are spliced together

Answer 57

Introns, exons

Question 58

RNA polymerase binds to DNA promoter sequences

Answer 58

STEP 1: INITIATION