You perform a series of experiments on the synthesis of thepituitary hormone prolactin, which is a single polypeptide chain199 amino acids long. in the first experiment, the mRNA coding forprolactin is translated in a cell free protein synthesizing systemcontaining ribosomes, amino acids, tRNAs, aminoacyl-tRNAsynthetases, ATP, GTP and the appropraite initiation, elongationand termination factors. Under these conditions, a polypeptidechain 227 amino acids long is synthesized. In a second experiment,the mRNA is translated in the same cell-free system to which youhave added SRP. In this case, translation stops after a peptideabout 70 amino acids long has been produced. In a third experiment,you ise the same cell free translation system to which you haveadded both SRP and endoplasmic reticulum vesicles, and you fingthat the prolactin mRNA no prduces a polypeptide that is 199 aminoacids long. Explain these results. Where would you find thepolypeptide produced in experiment 3?
You perform a series of experiments on the synthesis of thepituitary hormone prolactin, which is a single polypeptide chain199 amino acids long. in the first experiment, the mRNA coding forprolactin is translated in a cell free protein synthesizing systemcontaining ribosomes, amino acids, tRNAs, aminoacyl-tRNAsynthetases, ATP, GTP and the appropraite initiation, elongationand termination factors. Under these conditions, a polypeptidechain 227 amino acids long is synthesized. In a second experiment,the mRNA is translated in the same cell-free system to which youhave added SRP. In this case, translation stops after a peptideabout 70 amino acids long has been produced. In a third experiment,you ise the same cell free translation system to which you haveadded both SRP and endoplasmic reticulum vesicles, and you fingthat the prolactin mRNA no prduces a polypeptide that is 199 aminoacids long. Explain these results. Where would you find thepolypeptide produced in experiment 3?
