genetic exam 4

What is the biological definition of ‘to transcribe’?

Copying a specific DNA segment (a gene) into a complementary RNA molecule.

In the context of transcription, what is the purpose of regulated gene expression?

It allows for precise cell function and life maintenance

The transcription stage where the transcription apparatus assembles on the promoter is called __.

Initiation

What happens to DNA during the elongation stage of transcription?

It is threaded through RNA polymerase and unwound

To which end of the growing RNA strand are new nucleotides added during elongation?

The 3’ end

Which stage of transcription involves the separation of the RNA molecule from the DNA template?

Termination

What sugar is found in RNA, distinguishing it structurally from DNA?

Ribose

Which nitrogenous base is unique to RNA and replaces Thymine?

Uracil

How does the stability of RNA compare to that of DNA?

RNA is not stable, Whereas DNA is stable

What is the primary functional role of DNA in a cell

Storing and transmitting genetic information as a ‘master blueprint’

What three parts make up a typical DNA transcription unit?

Promoter, RNA-coding region, and terminator

Which part of the transcription unit determines which DNA stand is used as the template?

The promoter

True or false: The promoter sequence is usually transcribed into RNA

False.

What is the function of the RNA- coding region in a transcription unit?

It is the sequence of DNA nucleotides copied into an RNA molecule.

Where does transcription typically stop in relation to the terminator sequence?

Only after the terminator itself has been copied into RNA

In bacterial RNA polymerase, what is the ‘holoenzyme’ composed of?

Sigma factor and core enzyme

Which subunit of the bacterial RNA polymerase core enzyme is responsible for catalyzing RNA chain formation?

The Beta (β) subunit

What is the specific function of the σ (sigma) factor in the bacterial holoenzyme?

It allows the enzyme to recognize and bind to specific promoter sequences.

Which subunit of the bacterial core enzyme binds directly to DNA?

The Beta prime (β′) subunit.

What happens to the σ (sigma) factor after transcription initiation is complete?

It often detaches from the core enzyme.

The -10 consensus sequence in bacterial promoters is also known as the __.

Pribnow box

What is the consensus sequence for the bacterial -35 region?

TTGACA

What is the consensus sequence for the bacterial -10 region?

TATAAT

How does RNA polymerase facilitate the formation of a transcription bubble?