Question

in an experiment investigating the mechanism of protein secretion, researchers tracked the movement of radioactively labeled polypeptides in pancreatic cells. at various times after the labeling, samples of the cells were observed using an electron microscope to determine the location of the radioactively labeled polypeptides. figure 1 summarizes the results at 5 minutes, 15 minutes, and 30 minutes. the dark dots in the figure represent the radioactively labeled polypeptides.

sequence the pathway, starting with synthesis, that secretory proteins take from their synthesis to their release from the cell.

vesicles
golgi
endoplasmic reticulum
exterior of the cell

Explanation:

Secretory proteins are synthesized on ribosomes attached to the endoplasmic reticulum (ER). From the ER, they are transported in vesicles to the Golgi apparatus for further processing. After processing in the Golgi, they are packaged into secretory vesicles. Finally, these vesicles fuse with the plasma membrane to release the proteins to the exterior of the cell.

Answer:

endoplasmic reticulum → vesicles → golgi → vesicles → exterior of the cell