40 Questions
What is the primary function of RNA splicing in cells?
To produce mRNA
What is the primary function of elongation factors associated with RNA polymerase?
To decrease the likelihood of RNA polymerase dissociation before reaching the end of a gene
What is the term given to the RNA after 5ʹ- and 3ʹ-end processing and splicing have taken place?
mRNA
What is the role of ATP-dependent chromatin remodeling complexes in eukaryotic transcription?
To move or rescue stalled RNA polymerase
What is the byproduct of the splicing event that is removed from the exons?
Intron
What is the function of histone chaperones in eukaryotic transcription?
To partially disassemble nucleosomes in front of RNA polymerase
How many RNA molecules are involved in the machinery that catalyzes pre-mRNA splicing?
Five
What is the difference between the 5' and 3' ends of a bacterial mRNA compared to a eukaryotic mRNA?
Eukaryotic mRNA has a 5' cap and poly-A tail, while bacterial mRNA does not
What is the energy source required for the splicing event?
ATP
What is the purpose of the 5' cap and poly-A tail in eukaryotic mRNA?
To increase the stability of the RNA transcript
What is the first step in the splicing event?
First transesterification
What is the result of the first transesterification reaction?
Formation of a lariat
What is the primary difference between transcription in prokaryotes and eukaryotes?
Eukaryotes have chromatin structure, while prokaryotes do not
What is the relationship between transcription and RNA processing in eukaryotes?
Transcription is the first step in producing a mature mRNA
Why is RNA splicing necessary despite the removal of large numbers of introns?
To ensure accurate splicing and deal with the enormous variety of introns
What is the result of RNA splicing in eukaryotes?
The formation of a mature mRNA molecule
What is the primary role of RNA in the flow of genetic information in cells?
To transcribe DNA sequences into a usable form
What is the term used to describe the fundamental principle of genetic information flow in cells?
Central dogma of molecular biology
What is the name of the process by which the nucleotide sequence of a portion of DNA is copied into RNA?
Transcription
What is the term used to describe the functional RNAs that fold into precise three-dimensional structures?
Structural RNA
What is the characteristic feature of genomes in most multicellular organisms?
Surprisingly disorderly
What is the term used to describe the short sequences of DNA that code for protein?
Exons
What is the term used to describe the large blocks of seemingly meaningless DNA?
Introns
What is the current understanding of the roles of many non-coding RNAs?
Their roles are not yet fully understood
What is a common characteristic of protein-coding genes and their locations on chromosomes?
They are often located on different chromosomes.
What percentage of the human genome is represented in Figure 6-2?
1/2000th
What is indicated by the yellow triangles in Figure 6-2?
Positions where the human genome codes for a different amino acid than the Neanderthal genome.
What can be inferred about the function of the Txtl1 gene?
It has undergone positive selection.
What is the significance of the blue histogram in Figure 6-2?
It indicates the extent to which portions of the human genome are conserved with other vertebrate species.
What can be said about the proteins encoded by the genes in Figure 6-2?
Most of them are identical between humans and Neanderthals.
What is a likely scenario regarding the regions between the genes in Figure 6-2?
They may contain additional, currently unrecognized genes.
How many genes for non-coding RNAs are present in Figure 6-2?
6
What is unique about eukaryotic mRNAs compared to bacterial mRNAs?
They nearly always contain the information for only a single protein
What is the role of the CTD in eukaryotic RNA polymerase II?
To recruit mRNA processing factors
What is the significance of phosphorylation of the CTD in eukaryotic RNA polymerase II?
It recruits 5' capping enzymes
Why do genes transcribed by RNA Pol I and RNA Pol III not have capped 5' ends?
Because they do not have a CTD
What is the purpose of the RNA-processing proteins carried by RNA polymerase II?
To act on the newly synthesized RNA as it emerges from the RNA polymerase
Which RNA-processing enzymes do not travel with the polymerase?
Most RNA-processing enzymes
What is the role of the few critical components carried by the RNA polymerase II tail for RNA splicing?
To serve as a nucleation site for the remaining components
What is the result of the phosphorylation of the CTD in eukaryotic RNA polymerase II?
Recruitment of 5' capping enzymes
Learn how cells express their genetic information from DNA to RNA to protein. Understand the fundamental principle of gene expression, from transcription to protein synthesis.
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