Chapter 6: How Cells Read the Genome - Transcription and RNA Synthesis

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What is the characteristic of RNA molecules produced during transcription?

Double-stranded

Quadruple-stranded

Single-stranded (correct)

Triple-stranded

What is the function of RNA polymerase during transcription?

Replicating DNA

Catalyzing the formation of the phosphodiester (correct)

Unwinding the DNA helix

Synthesizing amino acids

What is the error rate of RNA polymerase during transcription?

One mistake for every 10^4 nucleotides copied (correct)

One mistake for every 10^7 nucleotides copied

One mistake for every 10 nucleotides copied

One mistake for every 10^2 nucleotides copied

What is the difference between RNA polymerase and DNA polymerase?

RNA polymerase does not require a primer, whereas DNA polymerase does Signup and view all the answers

How does RNA polymerase move along the DNA during transcription?

It moves in a stepwise manner Signup and view all the answers

What mechanism does RNA polymerase have to correct errors during transcription?

Proofreading mechanism Signup and view all the answers

What is the primary function of the σ factor in RNA polymerase holoenzyme?

To initiate the synthesis of RNA at the correct location Signup and view all the answers

What is the characteristic of transcription during the elongation mode of RNA synthesis?

It is highly inefficient and releases short, unproductive transcripts Signup and view all the answers

What is the role of general transcription factors in eukaryotic cells?

To help position RNA polymerase correctly at the promoter Signup and view all the answers

What is the result of the initial RNA synthesis during abortive initiation?

The release of short, unproductive transcripts Signup and view all the answers

What is the purpose of the termination signals in DNA?

To destabilize the polymerase’s hold on the RNA and release the transcript Signup and view all the answers

What is the characteristic of RNA polymerase during the initial steps of transcription?

It is relatively inefficient and releases short, unproductive transcripts Signup and view all the answers

What is the function of specific enzymes in protein synthesis?

To couple each amino acid to its appropriate tRNA molecule Signup and view all the answers

Where are proteins synthesized?

On polyribosomes Signup and view all the answers

What is the role of nucleotide sequences in mRNA?

To signal where to start protein synthesis Signup and view all the answers

What is the function of molecular chaperones in protein synthesis?

To guide the folding of most proteins Signup and view all the answers

What is the characteristic of single-strand RNA molecules?

They can fold into highly elaborate structures Signup and view all the answers

What is the role of tRNA synthetases in protein synthesis?

To ensure accuracy in protein synthesis Signup and view all the answers

What is the process by which amino acids are added to a growing polypeptide chain?

Elongation Signup and view all the answers

What is the role of chromatin-modifying proteins in transcription initiation in eukaryotes?

To modify histones and allow access to transcription factors Signup and view all the answers

What is the first modification of eukaryotic pre-mRNAs during transcription elongation?

RNA capping Signup and view all the answers

What is the purpose of the spliceosome during pre-mRNA splicing?

To produce a complex series of RNA-RNA rearrangements Signup and view all the answers

How do tRNA molecules match amino acids to codons in mRNA?

Through wobble base-pairing Signup and view all the answers

What is the function of the nucleolus in eukaryotic cells?

To synthesize ribosomal RNAs Signup and view all the answers

What is the role of activator proteins in transcription initiation in eukaryotes?

To recruit RNA polymerase to the promoter Signup and view all the answers