RNA Structure and Function Quiz

The ability of a molecule to catalyze (speed up) chemical reactions.

A type of RNA that has catalytic activity, meaning it can act as an enzyme.

The hypothetical period in early Earth's history where RNA served as the primary genetic material and catalyst.

A type of ribozyme that can self-replicate, making copies of itself.

The process by which organisms create copies of their genetic material (DNA or RNA).

The idea that life on Earth could have begun with RNA molecules.

The gradual replacement of RNA as the primary carrier of genetic information by DNA.

The ability of a molecule to store and transmit genetic information.

A region of DNA that is copied into RNA during transcription. It includes the promoter, the RNA-coding region, and the terminator.

The DNA strand that is used as a template for RNA synthesis. It serves as the basis for the sequence of the newly synthesized RNA molecule.

The DNA strand that is not used as a template for RNA synthesis. Its sequence is identical to the RNA transcript, except for the substitution of U for T.

A DNA sequence within a transcription unit that signals the start of transcription. It tells the transcription apparatus where to bind and start copying.

The first nucleotide in the RNA molecule that is transcribed. It is located at the 5' end of the RNA transcript and is determined by the promoter.

A DNA sequence within a transcription unit that signals the end of transcription. It causes the transcription apparatus to detach from the DNA template and release the RNA molecule.

The process by which genetic information encoded in DNA is used to synthesize RNA.

The RNA molecule that is synthesized during transcription. It carries the genetic information encoded in DNA to the ribosomes, where it is used to synthesize proteins.

In eukaryotes, RNA polymerase I specifically transcribes ribosomal RNA (rRNA) molecules, which are crucial components of ribosomes responsible for protein synthesis.

RNA polymerase II is responsible for transcribing pre-messenger RNA (pre-mRNA), which undergoes further processing to become mature mRNA and ultimately directs protein synthesis.

RNA polymerase III transcribes a variety of small RNA molecules, like tRNAs, small rRNAs, and some miRNAs and snRNAs, all critical for various cellular processes.

α-amanitin is a toxin that specifically inhibits RNA polymerase II by blocking its movement along the DNA template, leading to a dramatic slowdown in RNA synthesis.

Transcription is the process of copying genetic information from DNA into RNA, and it is divided into three phases: initiation, elongation, and termination.

Initiation is the first step in transcription, where the transcription apparatus assembles at the promoter region of a gene and begins RNA synthesis.

Elongation is the second step of transcription, where RNA polymerase unwinds the DNA, moves along the template strand, and adds nucleotides to the growing RNA molecule, effectively copying the genetic information.

Termination is the final stage of transcription, where the RNA polymerase recognizes a termination signal at the end of the gene and releases the newly synthesized RNA transcript.

DNA sequences that signal the start of transcription. RNA polymerase binds to them allowing it to position itself correctly.

The process where RNA polymerase repeatedly generates and releases short transcripts (2-6 nucleotides) while still bound to the promoter.

The stage of transcription where RNA polymerase changes conformation and detaches from the promoter, moving downstream to synthesize RNA.

A protein that helps RNA polymerase recognize and bind to promoter regions. It is often released after initiation.

A short region of unwound DNA (about 18 nucleotides) where RNA synthesis occurs.

The process by which RNA polymerase temporarily halts during transcription due to various factors like secondary structures or specific sequences

A type of proofreading mechanism where RNA polymerase slides backward along the DNA template during transcription, temporarily stopping the process.

Enzymes that relieve stress associated with unwinding and rewinding of DNA during transcription, similar to their role in DNA replication.

The accuracy of RNA polymerase in incorporating nucleotides into the growing RNA chain, with an occasional chance of error.

A type of proofreading during transcription where RNA polymerase momentarily pauses to check and correct errors in the RNA chain.

Process by which RNA polymerase disengages from the DNA template and releases the newly synthesized RNA molecule, often triggered by specific DNA sequences.

Specific sequences in the DNA template that trigger the termination of transcription.

Archaeal RNA polymerase is more similar to the eukaryotic RNA polymerase II in structure and amino acid sequence, unlike the bacterial RNA polymerase.

Archaea, like eukaryotes, have a TATA box in their promoters which is bound by a TATA-binding protein (TBP). This helps to initiate transcription at the correct position.

Archaea, while lacking a nucleus, possess histone proteins which help in organizing DNA into nucleosome-like structures.

Transcription in archaea shares many similarities with eukaryotes, suggesting a closer evolutionary relationship between the two domains than between archaea and bacteria.

Although archaeal transcription resembles eukaryotic transcription in many aspects, some of their transcription regulators are more similar to those found in bacteria.

RNA molecules found in mammalian testes, similar to miRNAs and siRNAs, that suppress the expression of transposable elements in reproductive cells.

Long RNA molecules in eukaryotes that don't code for proteins. They play diverse roles, including gene expression regulation.

An RNA interference-like system in prokaryotes. Small CRISPR RNAs (crRNAs) help destroy foreign DNA molecules.

RNA polymerase I, II, and III are present in all eukaryotic organisms.

RNA polymerase I transcribes rRNA, which is a crucial component of ribosomes, the protein-making machinery of the cell.

RNA polymerase II transcribes pre-mRNA, which is further processed into mature mRNA and carries the genetic information needed to produce proteins.

RNA polymerase III transcribes a variety of small RNAs, including tRNAs, small rRNAs, and some miRNAs and snRNAs, which play important roles in various cellular processes.

α-amanitin, a toxin from death cap mushrooms, specifically inhibits RNA polymerase II, halting RNA synthesis and leading to cellular damage and even death.

The three main stages of transcription are initiation, elongation, and termination. Initiation is the assembly of the transcription apparatus at the promoter, elongation is the synthesis of RNA, and termination is the release of the RNA transcript.

Initiation involves the binding of RNA polymerase to the promoter region, where the process of RNA synthesis begins.

Elongation is the process where RNA polymerase moves along the DNA template, unwinding it and adding nucleotides to the growing RNA strand, extending the RNA molecule.

A DNA sequence that is found about 35 nucleotides upstream of the start site in bacterial promoters. It helps RNA polymerase recognize the promoter.

A DNA sequence found approximately 10 nucleotides upstream of the start site in bacterial promoters. It facilitates unwinding of DNA for transcription.

A base substitution within the -10 and -35 consensus sequences that reduces the rate of transcription.

A base substitution within the -10 and -35 consensus sequences that increases the rate of transcription.

A protein that binds to the core RNA polymerase enzyme, forming a holoenzyme. This holoenzyme then identifies and binds to the promoter.

Also known as the upstream element, it's a third consensus sequence found in some bacterial promoters. Located between -40 and -60, it enhances transcription.

The stage in transcription when the holoenzyme binds to the promoter, unwinds the DNA, and begins RNA synthesis.

The region of DNA that is unwound during transcription, creating a single-stranded template for RNA synthesis.

Ancillary protein required for termination of transcription at rho-dependent terminators. It binds to RNA and moves toward the 3' end, unwinding the DNA-RNA hybrid.

A sequence rich in cytosine nucleotides upstream of a terminator, providing a binding site for the rho factor.

Terminators that rely on the rho factor to end transcription. They have a pause site for RNA polymerase and a rut site.

Terminators that can end transcription without the rho factor. They contain inverted repeats and a GC-rich region.