Practice Questions

The signal recognition particle contains a specific small cytoplasmic RNA molecule known as 7SL RNA, which guides newly synthesizing proteins to the ER.

Specific identity elements scattered across the acceptor stem and variable loops allow the synthetase to accurately identify its matching tRNA.

Ribosomal RNA forms the dense, intricately folded catalytic and structural core of both the large and small ribosomal subunits.

Prokaryotes handle all transcription with a single multi-subunit core RNA polymerase that relies on changeable sigma factors for promoter recognition.

miRNAs are tiny, non-coding RNA molecules that associate with RISC complexes to pair with matching mRNAs and suppress translation.

The AAUAAA consensus sequence is recognized by specific endonucleases that cleave the nascent RNA transcript before poly-A polymerase adds the tail.

The coding (sense) DNA strand matches the mRNA transcript sequence exactly, with the sole exception that thymine (T) is replaced by uracil (U).

The T$psi$C loop contains ribothymidine and pseudouridine, which are critical for anchoring the tRNA molecule to the large ribosomal subunit.

Accurate translation relies entirely on the precise hydrogen-bond pairing between three consecutive mRNA bases and three complementary tRNA bases.

In mammals and high eukaryotes, a single large 45S pre-rRNA transcript is synthesized and then cleaved to produce the 18S, 5.8S, and 28S rRNAs.