Bacterial Transcription

Question 1

RNA polymerase synthesises:

Answer 1

An RNA copy of the gene, using the antisense strand as a template

Question 2

An example of an allosteric protein is:

Answer 2

The lac repressor

Question 3

For which nitrogenous base does DNA substitute thymine?

Answer 3

Uracil

Question 4

The process of making an RNA copy of a gene is:

Answer 4

Transcription

Question 5

When cAMP levels are high in a cell:

Answer 5

Glucose levels are low

Question 6

In bacterial genomes, the ‘minus 10’ region is:

Answer 6

Ten nucleotides upstream of a gene

Question 7

Hairpin loop structures are found in:

Answer 7

mRNA

Question 8

The operon is kept off in the presence of glucose by:

Answer 8

In the presence of glucose, cAMP is low. Thus, cAMP will not bind to CRP. CRP will not bind to region b, the CRP site, which is needed for RNA polymerase to bind to the promoter.

Question 9

Inverted repeats make a:

Answer 9

Single-stranded loop and a double-stranded stem

Question 10

When given a choice of sugars to metabolise, E. coli will:

Answer 10

Preferentially break down glucose first

Question 11

The direction of synthesis is:

Answer 11

5’ to 3’ for both DNA and RNA

Question 12

True or false: mRNA has a base sequence which is complementary to the anticoding strand of DNA.

Answer 12

False

Question 13

A consensus sequence found in a bacterial promotor gene is:

Answer 13

An idealised sequence, which shares much sequence similarity for many genes

Question 14

Transcription begins when:

Answer 14

RNA polymerase recognises a promotor sequence, binds to the DNA, and synthesises RNA from the 5’ end to the 3’ end of the new piece.

Question 15

A high level of transcription can be achieved from the lac operon under the following conditions:

Answer 15

Low glucose, high cAMP, high lactose

Question 16

The global activation of this operon is carried out by:

Answer 16

CRP in the presence of cAMP, which activates other operons as well

Question 17

RNA polymerase binds to ____________ to begin transcription.

Answer 17

A region of DNA 10 to 100 bp upstream of the first ATG, called the promoter

Question 18

The coding strand of DNA is also known as the:

Answer 18

Non-template strand

Question 19

Binding of maltose to its activator protein will ultimately:

Answer 19

Activate cellular maltose breakdown

Question 20

An ___________ is defined as a cluster of genes transcribed together to give a single molecule of RNA.

Answer 20

Operon

Question 21

When a repressor protein binds to the operator sequence:

Answer 21

Transcription of the downstream gene is inhibited