Translation Flashcards

Flashcards about Translation

What is the role of mRNA in translation?

Encodes proteins.

What is the role of rRNA in translation?

Structural and enzymatic component of the ribosome.

What is the role of tRNA in translation?

Delivers amino acids to the ribosome.

What is a tRNA molecule?

Adaptor molecule that links an mRNA codon with a specific amino acid.

What sequence is found at the 3’ end of tRNA?

CCA-OH sequence.

What is the anticodon on tRNA?

Triplet of bases complementary to the mRNA codon.

What is wobble pairing?

Allows a single tRNA species to recognize more than one codon.

How are tRNAs charged?

Specific aminoacyl-tRNA-synthetases load tRNA molecules with amino acids.

What is the energy source for charging tRNAs?

Hydrolysis of ATP.

What is the E. coli ribosome composed of?

Large subunit (50S) and small subunit (30S).

What are the three tRNA sites on ribosomes?

E, P, and A sites.

Where can polyribosomes be found in eukaryotes?

Free in the cytoplasm or bound to rough endoplasmic reticulum (RER).

What are the three stages of translation?

Initiation, Elongation, Termination

What binds the 30S subunit in prokaryotic translation initiation?

Initiation factors (IFs) IF1 and IF3.

What sequence does 16S rRNA bind to in prokaryotic translation initiation?

Shine-Dalgarno sequence in the mRNA.

What binds after the 30S subunit complex in prokaryotic translation initiation?

The large 50S subunit.

What does the next aminoacyl tRNA bind to in prokaryotic translation elongation?

Elongation factor EF-Tu GTP and enters the A site.

What enzyme catalyzes peptide bond formation?

Peptidyl transferase.

What occurs during Translocation of the ribosome?

Hydrolysis of the GTP bound to EF-G.

What are the stop codons in prokaryotic translation termination?

UAA, UAG or UGA.

What is the role of release factors (RF1 or RF2) in translation termination?

Mimics shape of a tRNA and enters the A site with H2O molecule.

Where does transcription occur in prokaryotes?

Cytoplasm.

Where does translation occur in eukaryotes?

Cytoplasm.

Where does transcription occur in eukaryotes?

Nucleus.

What type of mRNA is produced in prokaryotes?

Polycistronic mRNA that encodes more than one protein.

What type of mRNA is produced in eukaryotes?

Monocistronic - encodes for one protein only.

What are the ribosome subunits in prokaryotes?

30S + 50S = 70S ribosome.

What are the ribosome subunits in eukaryotes?

40S + 60S = 80S ribosome.

Which initiation tRNA is used by prokaryotes?

fmet-tRNAfmet.

Which initiation tRNA is used by eukaryotes?

met-tRNAmet.