Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Why would the peptide prolactin be 28 amino acids longer if produced in vitro?

"You are studying the pituitary hormone prolactin, which is a single polypeptide chain of 199 amino acids. The mRNA encoding prolactin is translated in a cell free system containing ribosomes, amino acids, tRNAs, tRNA synthases, NTPs, and all translational initiation, elongation, and termination factors. Under these conditions a polypeptide chain of 227 amino acids is produced."

Provide 2 explainations for the discrepancy between the normal length of prolactin (199) and that observed in vitro (227).

and if you are bored....

if you add signal recognition particles to this system, a polypeptide of about 70 aa is produced. why?


both signal recognition particles and endoplasmic reticulum membrane vesicles are added to the system. This produces a polypeptide 199 amino acids long. why is this and where would you expect to find the finished protein?

1 Answer

  • 1 decade ago
    Favorite Answer

    hahahahahah are you in Bio 213 at A&M

Still have questions? Get your answers by asking now.