Transcription, Genetic Code, Translation

Question 1

Element found downstream of the transcription start site (Pribnow box and -35 in eukaryotes; TATA box, CAAT box, GC box in eukaryotes)

Answer 1

Promoter

Question 2

Promoter, -10 nt downstream of tss (prokaryotes)

Answer 2

Pribnow Box

Question 3

Promoter, -30 to -100 bp downstream of tss (eukaryotes)

Answer 3

TATA box

Question 4

Element that increases transcription, found 1000s of nt’s downstream of tss (eukaryotes)

Answer 4

Enhancer

Question 5

An enhancer element that is responsive to regulation from an environmental stimuli, for example hormones or metals (eukaryotes)

Answer 5

Response element

Question 6

Trans-acting protein that binds to promoter or initiator site to promote transcription (eukaryotes)

Answer 6

Transcription factor

Question 7

Synthesizes single rRNA transcript (eukaryotes)

Answer 7

RNA Pol I

Question 8

Transcribes tRNAs and 5S rRNA (eukaryotes)

Answer 8

RNA Pol II

Question 9

Transcribes mRNA (eukaryotes)

Answer 9

RNA Pol III

Question 10

Regulatory subunit of RNA polymerase, binds -35 region (prokaryotes)

Answer 10

Sigma factor

Question 11

Multi-protein coding genetic cassette under regulation (prokaryotes)

Answer 11

Operon

Question 12

Binds operator site of operon and prevents transcription (prokaryotes)

Answer 12

Repressor

Question 13

Binds and inactivates repressor (allolactose in lac operon, prokaryotes)

Answer 13

Inducer

Question 14

Un-translated region of RNA that is removed by splicing

Answer 14

Intron

Question 15

Expressed region of RNA that remains after splicing

Answer 15

Exon

Question 16

Adenosine nucleotide in the center of an intron, U2 binds here

Answer 16

Branch Site

Question 17

Splicing intermediate after the first splicing reaction occurs, cyclic intermediate connecting 5’-end of intron to the branch site

Answer 17

Lariat

Question 18

Ribonucleoprotein subunit involved in mRNA processing through splicing

Answer 18

snRNP

Question 19

Write out the chemical equations for the two steps in the reaction catalyzed by aminoacyl tRNA transferase. Include all products and reactants.

Step 1: amino acid activation

Step 2: aminoacyl transfer to the tRNA

Answer 19

amino acid + ATP → aminoacyl-AMP + PPi

aminoacyl-AMP + tRNA → aminoacyl-tRNA + AMP

Question 20

Write the chemical equation for the net reaction catalyzed by aminoacyl transferase.

Answer 20

amino acid + ATP + tRNA → aminoacyl-tRNA + AMP + 2Pi

Question 21

“Coding center” where mRNA pairs with tRNA anti-codon end

Answer 21

30S subunit

Question 22

“Catalytic center” where aminoacyl end of tRNA binds and the peptide chain is synthesized

Answer 22

50S subunit

Question 23

GTPase which shifts register of tRNAs from A-P sites to P-E sites, uses GTP

Answer 23

EF-G

Question 24

Utilizes GTP to recruit charged tRNAs to the A site of the ribosome

Answer 24

EF-Tu

Question 25

Binds A site to prevent premature ribosomal assembly

Answer 25

IF-1

Question 26

GTPase which guides initiator tRNA to the 30S ribosomal pre-initiation complex

Answer 26

IF-2

Question 27

Binds E site to prevent premature ribosomal assembly

Answer 27

IF-3

Question 28

Binds A site when a stop codon is present on the mRNA, ends translation

Answer 28

RF-1

Question 29

Charges tRNAs with activated amino acids

Answer 29

Aminoacyl tRNA synthetase

Question 30

3 nt sequence on tRNA that is reverse complement to codon

Answer 30

Anticodon

Question 31

3 nt sequence on mRNA which codes for an amino acid

Answer 31

Codon

Question 32

1st base of the anticodon (3rd base of the codon) has more flexibility in base pairing, leads to degeneracy in codons

Answer 32

Wobble Hypothesis

Question 33

Purine rich sequence downstream of start codon which binds to 16S rRNA of 30S subunit to initiate translation

Answer 33

Shine-Delgarno Sequence

Question 34

The ribosome has three sites for binding tRNAs. What are they?

Answer 34

A site: * “Aminoacyl site” * where charged tRNAs enter P site: * “Peptidyl site” * Where the growing peptidyl chain is found E site: * “Exit site” * Where the uncharged tRNAs exit