Protein Synthesis and Turnover

These flashcards cover the key concepts of protein synthesis and turnover, including the stages of translation, the role of ribosomes and various factors, and differences between bacterial and eukaryotic processes.

What are the three steps of protein translation?

Initiation, Elongation, Termination.

What is the start codon for protein synthesis?

AUG (Methionine) begins the polypeptide chain.

What are the tRNA binding sites on the ribosome?

A (aminoacyl), P (peptidyl), and E (exit) sites.

What is the role of elongation factor Tu (EF-Tu) during translation?

Delivers aminoacyl-tRNAs to the A site and protects them from hydrolysis.

What mechanism is involved in peptide bond formation?

Catalyzed by a site on the 23S rRNA in the 50S subunit.

How does translocation of tRNAs and mRNA occur?

By EF-G, which moves the deacylated tRNA to the E site.

What are the major differences between bacterial and eukaryotic protein synthesis?

Eukaryotic ribosomes are larger, have a different initiator tRNA, and participate in a circular mRNA structure.

What are the two methods by which eukaryotes direct newly synthesized proteins?

Cytoplasmic delivery post-translation and the secretory pathway through the endoplasmic reticulum.

What is the function of the signal recognition particle (SRP)?

Binds the signal sequence and halts protein synthesis to translocate the ribosome to the ER.

What controls the regulation of protein synthesis?

mRNA presence, stability regulations, and small RNAs like miRNA.