RNA Synthesis Terms & Definitions - Biology Test 3

What is the transcribed RNA called?

transcript

What is the difference between the ribose sugar and deoxyribose sugar?

ribose has a -OH group on the number 2 carbon

What replaces thymine in RNA?

Uracil

Is RNA usually single or double stranded?

single stranded

What is the stability of RNA?

easily degraded

How is RNA secondary structure formed?

folding of the primary structure causing hairpins.

Messenger RNA (mRNA)

carries genetic code for proteins

Transfer RNA (tRNA)

helps incorporate amino acids into polypeptide chain

Ribosomal RNA (rRNA)

Structural and functional components of the ribosome

Small Nuclear RNA (snRNA)

processing of pre-mRNA

smal nucleolar RNA (snoRNA)

processing and assembly of RNA

MicroRNA (miRNA)

inhibits translation of mRNA

small interfering RNA (siRNA)

Triggers degradation of other RNA molecules

What is the template strand called?

non-coding or nonsense strand

What is the non-template strand called?

coding or sense strand

Where do nucleotides get adding on the RNA molecule?

the 3' end

What are the three steps in transcription?

initiation, elongation, and termination

What are the core enzymes in prokaryote transcription initian?

alpha, beta, beta' and omega

What does alpha do?

help assembly/ promote interactions with regulatory proteins.

What does beta do?

active in catalysis

What does beta' do?

binds to DNA

What does omega do?

enzyme assembly

What helps make up the holoenzyme?

sigma

What does the sigma do?

promoter recognition

What happens during transcription initiation?

RNA polymerase binds to promoter

What happens during transcription elongation?

-RNA polymerase moves downstream

-unwinding DNA and elongating RNA transcript at 3' end

-DNA strands reform as double helix

When is RNA transcription initated?

when core RNA polymerase binds to the promoter with the help of sigma.

What happens during transcription termination?

RNA polymerase stops at terminator

Rho-independent termination

when inverted repeats form a hairpin followed by a string of uracils

Rho-dependent termination

Rho binds to an unstructured region of RNA and moves towards its 3' end. When RNA polymerase encounters a terminator sequence, it pauses and rho catches up. Using helicase activity, rho unwinds the DNA-RNA hybird and brings transcription to an end.

What are the promoters of genes transcribed by RNA polymerase 11? (eukaroytes)

Regulatory promoter and core promoter.

What are the elements of the core promoter?

TFIIB recognition element, TATA box, Initiator element, downstream core promoter element.

In rho-dependent transcription termination, what does the rho factor bind to?

mRNA

In eukaryotes, what initially binds to the TATA box on the DNA template?

TFIID