Molecular Genetics: Transcription

Question 1

RNA polymerases

Answer 1

synthesize RNA from 5’ to 3’ without a primer

Question 2

sigma

Answer 2

protein in prokaryotes that binds to RNA polymerase and promoter regulatory sequences

Question 3

holoenzyme

Answer 3

sigma, DNA, RNA polymerase complex

Question 4

different sigmas for

Answer 4

regulation of gene expression for different stress responses

Question 5

-10 box and -35 box

Answer 5

areas in the promoter region in prokaryotes to determine direction of transciption

Question 6

rudder

Answer 6

structure in RNA polymerase that guides template and coding strands to appropriate channels

Question 7

zipper

Answer 7

structure in RNA polymerase that separates RNA from DNA template

Question 8

termination signal

Answer 8

self-complementary RNA sequence that forms a hairpin loop to allow RNA to dissociate from DNA

Question 9

transcription start site (+1)

Answer 9

upstream of protein-coding genes

Question 10

5’ UTR and 3’ UTR

Answer 10

stabilize mRNA and involved in translation regulation

Question 11

RNA polymerase II

Answer 11

in eukaryotes transcribes protein encoding genes

Question 12

RNA polymerase I

Answer 12

in eukaryotes synthesizes ribosomal RNAs

Question 13

RNA polymerase III

Answer 13

in eukaryoes synthesizes tRNA and small regulatory RNAs

Question 14

RNA polymerases IV and V

Answer 14

plant specific and regulatory RNAs

Question 15

basal transcription factor

Answer 15

proteins absolutely necessary for transcription to happen (sigma in prokaryotes, TATA binding protein in eukaryotes)

Question 16

-30 position in eukaryotes

Answer 16

TATA box

Question 17

in eukaryotes transcription ends when

Answer 17

polyA signal is transcribed

Question 18

primary transcript/ pre-mRNA

Answer 18

initial product of transcription in eukaryotes

Question 19

RNA splicing

Answer 19

removing introns and joining exons together

Question 20

small nuclear RNAs (snRNPs)

Answer 20

catalyze RNA splicing

Question 21

spliceosome

Answer 21

snRNPs bound to RNA - intron guided into a self-complementary loop which is cleaved

Question 22

isoforms

Answer 22

different ways primary RNAs can be spliced to create a different version of a protein

Question 23

5’ cap

Answer 23

modified guanine and triphosphate

Question 24

polyA tail

Answer 24

added to the 3’ end by polyadenylate polymerase

Question 25

what to the 5’ cap and polyA tail do?

Answer 25

proteins bind to them to help facilitate mRNA exit from the nucleus and prevent degradation and function in translation initiation