Which statement best describes the role of snRNPs in RNA splicing?

Which statement best describes the role of snRNPs in RNA splicing?

• A. They catalyze transcription of RNA
• B. They cap the 5' end of RNA
• C. They are components of the spliceosome that help remove introns
• D. They polyadenylate the 3' end of RNA

Answer: (C)

Small nuclear ribonucleoproteins (snRNPs) are essential components of the spliceosome, the molecular machine that removes introns from pre-mRNA. They carry small nuclear RNA that base-pairs with conserved sequences at splice sites, guiding spliceosome assembly and positioning the catalytic residues needed for splicing. Through two successive transesterification reactions, the intron is excised as a lariat and the adjacent exons are joined, producing a mature mRNA. The other processes—transcription, 5' capping, and 3' polyadenylation—are carried out by different enzymatic systems, not by snRNPs.

Small nuclear ribonucleoproteins (snRNPs) are essential components of the spliceosome, the molecular machine that removes introns from pre-mRNA. They carry small nuclear RNA that base-pairs with conserved sequences at splice sites, guiding spliceosome assembly and positioning the catalytic residues needed for splicing. Through two successive transesterification reactions, the intron is excised as a lariat and the adjacent exons are joined, producing a mature mRNA. The other processes—transcription, 5' capping, and 3' polyadenylation—are carried out by different enzymatic systems, not by snRNPs.