Translation Flashcards
What is a codon?
Triplets of nucleotides.
When does translation begin in prokaryotes?
Translation begins before transcription is completed.
Where does transcription and translation take place in eukaryotes?
Transcription occurs in the nucleus.
Translation occurs in the cytoplasm.
What are the requirements for translation?
- ribosomes
- tRNA
- activating enzymes
- mRNA (template).
Name the activating enzyme family and its function.
Aminoacyl-tRNA synthetases.
Attach specific amino acids to their appropriate tRNAs forming charged tRNAs.
Name the two subunits and the four sites on a ribosome.
Subunits: small and large.
Sites: E, P, A and T.
Name the three phases of translation.
- Initiation
- Elongation
- Termination.
Describe initiation.
An initiation complex forms, consisting of the initiator tRNA charged with methionine and the small ribosomal subunit bound to mRNA triggers the beginning of translation.
Describe elongation.
Ribosome moves along mRNA in a 5’ to 3’ direction. Polypeptides grow from N to C terminus. Charged tRNAs bring amino acids to the ribosome sequentially.
Describe termination.
Presence of a stop codon in the A site of the ribosome causes translation to terminate. Completed protein is released.
Define translation.
The process whereby mRNA is decoded into protein.
