9!!Molecular Mechanisms of Disease Quiz

Parts of a gene that are included in the final mRNA product.

Non-coding sequences within a gene that are removed during mRNA processing.

The process of removing introns from pre-mRNA and joining exons together.

Specific sequences at the boundaries of exons and introns where the RNA is cut and joined.

Small nuclear ribonucleoproteins; complexes of proteins and small nuclear RNAs crucial to the splicing process.

The process of creating RNA from a DNA template inside the nucleus.

RNA molecule that carries the genetic code from DNA to the ribosomes for protein synthesis.

The initial RNA molecule created during transcription, later processed into mature mRNA.

The enzyme responsible for creating pre-mRNA during transcription.

A part of RNA polymerase that organizes factors for processing pre-mRNA, including capping, polyadenylation, and splicing.

The initial RNA molecule created during transcription, also called heterogeneous nuclear RNA (hnRNA). It is a longer transcript that contains both introns and exons and will be further processed to remove introns and become mature mRNA.

Another name for pre-mRNA; the initial RNA transcript produced during transcription, containing both introns and exons.

The entire length of DNA that is transcribed into pre-mRNA, including both introns and exons.

Pre-mRNA is always associated with proteins; it is not naked.

Pre-mRNA has a short lifespan because it is quickly processed into mature mRNA.

Small nuclear ribonucleoproteins (snRNPs) are essential for splicing pre-mRNA into mature mRNA. They recognize splice sites and help to cut out introns and join exons together.

The spliceosome is a large molecular machine responsible for removing introns from pre-mRNA. It's made up of snRNPs and associated proteins.

U1 snRNP binds to the 5' splice site of pre-mRNA, recognizing the G/GU sequence. The U1 snRNA within the snRNP has a sequence complementary to the 5' splice site.

U2 Auxiliary Factor (U2AF) is a protein that binds to the polypyrimidine tract and 3' splice site of pre-mRNA. It then attracts U2 snRNP.

U4/U6 and U5 snRNPs join the splicing complex. U4 snRNA detaches, allowing U6 to pair with U2 snRNA. This displaces U1, and U6 then binds to the 5' splice site.

Pre-mRNA is the initial RNA transcript created during transcription. It contains both introns and exons. It is also referred to as heterogeneous nuclear RNA (hnRNA).

Pre-mRNA is also called heterogeneous nuclear RNA (hnRNA) because it is a diverse mix of RNA molecules found in the nucleus.

The transcriptional unit is the entire length of DNA that's transcribed into pre-mRNA, including both introns and exons.

Pre-mRNA is always associated with proteins, forming ribonucleoprotein complexes. It's never 'naked' RNA.

Pre-mRNA has a short lifespan because it is quickly processed to remove introns and prepare for translation.

Introns are non-coding sequences within a gene that are removed during mRNA processing. They are not included in the final mature RNA product.

Exons are coding sequences within a gene that are included in the mature RNA product. They are the 'expressed' parts of the gene.

Splice sites are specific sequences at the boundaries of exons and introns where the RNA is cut and joined. They are highly conserved.

snRNPs are small nuclear ribonucleoproteins. They are complexes of proteins and small nuclear RNAs (snRNAs) that are essential for splicing pre-mRNA.

Exonic splicing enhancers (ESEs) are sequences within exons that help recruit snRNPs, promoting efficient splicing. They help ensure the correct exons are included in the final mRNA product.

U1 snRNP binds to the 5' splice site of pre-mRNA, which is located at the beginning of an intron.

U2AF (U2 Auxiliary Factor) helps U2 snRNP bind to the branch point sequence, which is a specific region within an intron.

U4/U6 and U5 snRNPs bind to the pre-mRNA, and then U4 snRNA is removed. This allows U6 to pair with U2 snRNA, displacing U1 and associating with the 5' splice site.

U6 is a ribozyme, meaning it's an RNA molecule that catalyzes, or speeds up a chemical reaction. It catalyzes the first cleavage (Rx1) of the 5' splice site, releasing the 5' exon and creating a lariat intron.

The second cleavage reaction (Rx2) at the 3' splice site removes the lariat intron and joins the two exons together. The snRNPs are then released and can participate in splicing other introns.

Groups of tRNA genes arranged in tandem (one after another) on a chromosome.

A region of DNA that separates individual tRNA gene units within a cluster, preventing them from being transcribed together.

A specific DNA sequence within a tRNA gene that signals where transcription should begin.

The series of modifications made to a newly transcribed tRNA molecule, including trimming and base modifications, that prepare it for its role in protein synthesis.

tRNA transcripts need processing to become a functional molecule for protein synthesis. The steps include removing extra nucleotides (trimming) and modifying bases, ensuring correct structure and function.