BGM1004/L11 Transcripts

Question 1

How are clustered genes often transcribed?

Answer 1

As a single molecule of mRNA

Question 2

What is a polycistronic mRNA?

Answer 2

mRNA corresponding to multiple genes whose expression is controlled by a single promoter and terminator

Question 3

What kind of genes are single transcription units?

Answer 3

Monocistronic

Question 4

When is a poly A tail added to mRNA?

Answer 4

After transcription

Question 5

How many attachment points do transcription promoters have?

Answer 5

1 or 2

Question 6

What does a region upstream (5’) of a gene contain?

Answer 6

Nucleotide sequences for association of transcription factors

Question 7

What enzyme do transcription factors recruit?

Answer 7

RNA polymerase

Question 8

What are conserved sequences recognised by in prokaryotes?

Answer 8

Sigma factor

Question 9

What is a holoenzyme made up of? (2)

Answer 9

RNA polymerase
Sigma factor

Question 10

At which point does sigma factor recognise different sequences?

Answer 10

-35 & -10

Question 11

What would a mutation to a single sigma factor affect?

Answer 11

Expression of the set of genes it regulates

Question 12

What is a microarray?

Answer 12

DNA corresponding to each gene in the organism’s genome spotted onto a slide

Question 13

How are introns removed from pre-mRNA transcript?

Answer 13

Splicing

Question 14

What feature of introns and exons ensure they are spliced correctly?

Answer 14

Conserved sequences at boundaries

Question 15

What would a mutation in the intron sequence affect?

Answer 15

Splicing

Question 16

What would a mutation in the exon sequence affect?

Answer 16

Sequence of coded protein

Question 17

What can alternative splicing create?

Answer 17

Multiple products from each gene

Question 18

What is the difference of transcriptase in alternative splicing?

Answer 18

Can become much more complex than genome

Question 19

What is the small ribosomal subunit responsible for?

Answer 19

Finding start of ORFs in mRNA and interpreting each codon

Question 20

What does the large ribosomal subunit house?

Answer 20

Protein synthetic peptidyl transferase centre

Question 21

What is the Shine-Dalgarno sequence?

Answer 21

A sequence of bases that define the start of an ORF
UAAGGAGGU(N)5-7AUG

Question 22

What would the mutation of a Shine-Dalgarno sequence cause?

Answer 22

Reduced translation of ORF it is associated with

Question 23

What does eukaryotic translation initiation depend on?

Answer 23

5’ CAP on mRNA

Question 24

What causes binding of the large ribosomal subunit?

Answer 24

Kozak consensus

Question 25

Why can’t translation catch up with transcription in eukaryotes?

Answer 25

Translation and transcription occur in different cellular compartments

Question 26

What codon/amino acid does translation start on?

Answer 26

AUG/methionine