Practice Questions

Nucleic acid strands align anti-parallelly; therefore, the 5'-AUG-3' codon pairs with the 3'-UAC-5' (or 5'-CAU-3') anticodon.

A polysome (or polyribosome) consists of a single mRNA strand being translated simultaneously by several moving ribosomes to amplify protein yield.

snRNAs combine with specific proteins to form snRNPs ("snurps"), which build the spliceosome machinery responsible for removing introns.

A triplet code consisting of three consecutive nucleotides provides the minimum variations (43=64) needed to code for 20 amino acids.

Polycistronic mRNA is characteristic of prokaryotes, where a single promoter controls an operon containing multiple related open reading frames.

Ribonucleases (RNases) degrade mRNA molecules once their translational utility is exhausted, preventing overproduction of proteins.

Unlike other rRNAs transcribed by RNA Polymerase I in the nucleolus, 5S rRNA is transcribed by RNA Polymerase III in the nucleoplasm.

While the 2D layout is a cloverleaf, the functional 3D conformation is an L-shape stabilized by complex non-Watson-Crick hydrogen bonding.

Post-transcriptional enzymatic modifications generate unique bases in tRNA to stabilize its complex three-dimensional tertiary structure.

The carboxyl group of the amino acid forms a high-energy ester linkage with the 3'-OH group of the terminal adenosine on the tRNA.