Week 1

Question 1

Promoter

Answer 1

the DNA sequence that controls where RNA polymerase binds to the DNA and initiates RNA synthesis

Question 2

Terminator

Answer 2

where RNA polymerase stops and releases the RNA transcript before dissociating from the DNA

Question 3

Gene

Answer 3

entire DNA sequence including all of the control elements

Question 4

Promoters/terminators vs. start/stop codons

Answer 4

Transcription promoters and terminators, which control where transcription begins and ends, respectively, should not be confused with translation start and stop codons, which function in the cytoplasm to define where protein synthesis begins and ends.

Question 5

ORF

Answer 5

region located between the start codon and the stop codon is referred to as the open reading frame

Question 6

Polycistronic mRNA

Answer 6

Due to the selective pressure for prokaryotic organisms to economize on the sizes of their genomes, bacterial genes often code for mRNAs with multiple ORFs

Question 7

Monocistronic mRNA

Answer 7

Eukaryotic: mature forms contain only one ORF encoding only one protein

Question 8

Exon

Answer 8

sequence in a pre-mRNA that will ultimately become part of the “expressed” mature mRNA, and is not specifically
in coding sequence

Question 9

Intron

Answer 9

sequence in a pre-mRNA that is removed during RNA processing and is not found in the final mature RNA

Question 10

transcription signals are read:

Answer 10

in the nucleus by RNA polymerases

Question 11

translational signals are read:

Answer 11

in the cytoplasm by the ribosomes

Question 12

Transcription

Answer 12

is the process by which RNA is synthesized by RNA polymerases using a segment of one strand of the DNA as a template

Question 13

The minimal functional form of an RNA polymerase is called the:

Answer 13

core enzyme

Question 14

RNA polymerase (RNAP I) 
RNA polymerase (RNAP II) 
RNA polymerase (RNAP III)

Answer 14

1. ribosomal RNA genes
2. genes encoding mRNAs and genes encoding many small RNAs involved in mRNA processing
3. 5S ribosomal RNA genes, tRNA genes, and genes encoding many small RNAs with different functions

Question 15

Holoenzyme

Answer 15

form of RNA polymerase that recognizes and binds to the promoter

Question 16

transcription pre-initiation complex or (PIC)

Answer 16

Instead of recognizing the promoter DNA directly like its bacterial counterpart, eukaryotic RNAPII recognizes a protein-DNA complex pre-assembled at the promoter region

Question 17

The large size and complexity of eukaryotic RNA polymerase II are related to

Answer 17

the enormous set of regulatory pathways that modulate pol II transcription

Question 18

The location and basal level of transcription by RNA polymerase are controlled by

Answer 18

the core promoter region

Question 19

Core promoter region

Answer 19

These include the TFIID recognition elements, which consist of the TATA box, and the initiator region or INR, the TFIIB recognition element or BRE, and the downstream promoter element or DPE.

Question 20

Transcription steps

Answer 20

Initiation, elongation, termination

Question 21

Steps of transcription initiation

Answer 21

(1) promoter location by RNA polymerase;
(2) binding of RNA polymerase to the DNA;
(3) separation of the DNA strands by RNA polymerase to form the open complex; and
(4) movement of the RNA polymerase from the promoter

Question 22

T/F: Initiation of transcription does not require a primer to begin polynucleotide synthesis.

Answer 22

True

Question 23

Transcription elongation

Answer 23

the DNA bubble is propagated down the template inside the active site of the RNA polymerase

Question 24

Transcription termination

Answer 24

(1) the cessation of RNA polymerase movement;
(2) the release of the transcript; and
(3) the release of RNA polymerase

Question 25

Prokaryotic core RNA pol

Answer 25

2 diff large subunits called b’ and b, and two identical small a subunits. Prok generally have only one form of the RNA polymerase core enzyme, but different holoenzyme forms consisting of one of several initiation factors called sigma. The holoenzyme recognizes and binds to the “core promoter” region. The antibiotic rifampicin, which is used to treat tuberculosis infections, specifically targets the b subunit of bacterial RNA polymerase.