Module 8

Question 1

________: encodes sequence of amino acids in polypeptide

__________: major component of ribosomes

__________: carries amino acids to ribosomes during protein synthesis

_________: helps remove introns from mRNA molecules (eukaryotes)

_____________: regulate gene expression by binding to mRNA molecules (eukaryotes)

_____________: (siRNA) double-stranded regulatory RNA, interacts with mRNA (eukaryotes)

___________: interacts with telomerase, template for elongating telomeres (eukaryotes)

Answer 1

mRNA
rRNA
tRNA
snRNA
miRNA
siRNA
telomerase RNA

Question 2

___________ is the synthesis of a single-stranded RNA molecule by RNA
polymerase

Answer 2

transcription

Question 3

What does RNA polymerase use to
assemble a complementary, antiparallel strand of ribonucleotides?

What is complementary to the template strand?

Answer 3

the template (non-coding) strand of the DNA

the coding strand

Question 4

Is DNA or mRNA associated with Regulator, Promoter, Terminator?

Is DNA or mRNA 5ʹ and 3ʹ UTR, RBS (ribosomal binding sequence), Start and Stop
Codons, coding region?

Answer 4

DNA

mRNA

Question 5

Where is the promoter located?

Answer 5

upstream to the start of transcription

Question 6

what holds
the information needed to
synthesize a protein product?

Answer 6

coding region

Question 7

Where is the terminating region located?

Answer 7

downstream to the coding segment

Question 8

What enzyme is responsible for transcribing a DNA sequence into a complementary RNA sequence?

What is the enzyme composed of?

Answer 8

rna polymerase

core enzyme that binds a sixth subunit, called the sigma subunit

Question 9

T/F core enzyme:
cannot transcribe RNA from a DNA template but can bind the promoter or initiate RNA synthesis without the  subunit

Answer 9

FALSE, core enzyme:
▪ CAN transcribe RNA from a DNA template but CANNOT bind the promoter or initiate RNA synthesis without the  subunit

Question 10

RNA polymerase is attracted to promoters by what?

Answer 10

the presence of consensus
sequences

Question 11

Rho-independent (aka intrinsic):
mRNA forms what?

Rho-dependent: rho (ρ) protein
binds what in mRNA?

Answer 11

hairpin/ stem-loop

rho utilization (or rut) site in mRNA

Question 12

Which of the following is not shared between Rho
dependent and Rho-independent termination of
transcription?

a) both are found in bacteria
b) Rho utilization site (rut)
c) poly-U tract at mRNA 3’ end
d) poly-A tract in template strand
e) formation of hairpin/stem-loop structure

Question 13

T or F Eukaryotic transcription is more complex than bacterial transcription

Answer 13

True

Question 14

eukaryotic DNA associated with
many proteins to form what?

Answer 14

chromatin

Question 15

heterochromatin vs. euchromatin

Answer 15

heterochromatin is tightly packed, and transcriptionally inactive chromatin is loosely packed and transcriptionally active

Question 16

The promoters for RNA pol II genes are highly __________ with different overall lengths and number and types of consensus sequences

Answer 16

diverse

Question 17

RNA Polymerase I – (how many?) rRNA

▪ RNA Polymerase II – __RNA and most snRNA for spliceosomes, also miRNA and siRNA

▪ RNA Polymerase III – __RNA (plus miRNA, siRNA, one snRNA and one rRNA)

Answer 17

1. 3 rRNA
2. mRNA
3. tRNA

Question 18

most common Eukaryotic Promoter Elements

Answer 18

the TATA box, or the Goldberg-Hogness box, 5’-TATAAA-3’, located at about position −25 (upstream of start codon)

Question 20

1. A CAAT box is often found near the?
2. A GC-rich box (consensus 5-GGGCGG-3) is located at?

Answer 20

1. −80 position
2. −90, or further upstream

Question 21

1. initial committed complex: TFIID
   (transcription factor IID) binds at promoter
2. Minimal initiation complex: _____ ___________ joins along with three other TFII proteins
3. ____________ complex: two more TFII
   proteins join

Answer 21

1. initial committed complex
2. RNA polymerase
3. Preinitiation complex

Question 22

what do Enhancer sequences do?

Answer 22

increase the level of transcription of specific genes

Question 23

DNA elements that act at a distance
to repress transcription of their target genes

Answer 23

Silencer sequences

Question 24

what transcribes a gene past a poly(A) signal sequence?

Answer 24

RNA polymerase II

Question 25

Allosteric model: After passing the polyA signal sequence, RNA polymerase II is destabilized due to what?

Answer 25

the release of elongation factors or the binding of termination factors. Termination occurs.

Question 26

Torpedo model: An exonuclease binds past the polyA sequence in mRNA that is still being transcribed and degrades it in a 5’ to 3’ direction. Exonuclease catches what?

Answer 26

RNA polymerase and ‘bumps’ it off.

Question 27

In ______________ especially, we refer to pre-mRNA (pre-processing) and mature mRNA (postprocessing).

Answer 27

eukaryotes

Question 28

T or F The 5ʹ cap is a modified guanine nucleotide

Answer 28

true

Question 29

five Functions of the 5' Cap and 3' poly-A tail

Answer 29

1. Protection of mRNA 2. Facilitating transport of mRNA out of nucleus 3. Enhancing translation efficiency 4. Facilitating subsequent intron splicing (G cap)

Question 30

Introns generally contain three short sequences what are they?

Answer 30

5' splice site 3' splice site branch site

Question 31

in intron splicing, the 5' splice site guanine forms bond with branch site ________, resulting in formation of ‘lariat’ structure

Answer 31

adenine

Question 32

which group of introns are capable of splicing themselves?

Answer 32

group I and group II introns are capable of splicing themselves

Question 33

group I and II introns are classified as?

Answer 33

ribozymes (RNA enzymes)

Question 34

Large eukaryotic genomes often express more proteins than there are genes in the genome due to what? alternative pre-mRNA processing

Answer 34

alternative pre-mRNA processing

Question 35

what is Alternative splicing?

Answer 35

pre-mRNA can be spliced in different patterns in different cell types

Question 36

1. Alternative __________: can initiate transcription at distinct +1 start points in different cell types Alternative _____________: varying localizations of polyadenylation can produce different mature mRNAs

Answer 36

1. alternative promoters 2. Alternative polyadenylation

Question 37

one of many eukaryotic genes that features alternative splicing

Answer 37

rat tropomyosin

Question 38

single gene responsible for how many mRNA transcripts?

Answer 38

9

Question 39

1. All RNAs are produced by what? 2. Only _____ is translated into protein

Answer 39

1. transcription 2. mRNA