Question

Cells of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track the location of these proteins in a cell. In this case, we are tracking an enzyme that is eventually secreted by pancreatic cells. Which of the following is the most likely pathway for movement of this protein in the cell?
a. ER -Golgi - nucleus
b. Golgi -ER - lysosome
c. nucleus - ER - Golgi
d. ER - Golgi - vesicles that fuse with plasma membrane
e. ER - lysosomes - vesicles that fuse with plasma membrane

Answer 1

is A, because the process are in order and all of them have relationship with proteins

Answer 2

Answer: ER - lysosomes - vesicles that fuse with plasma membrane

Explanation: The principal function of pancreas is production of insulin and glucagon hormones. These hormones are involved in metabolism of glucose and thus involved in energy production of the body. Now, the organelles which are responsible for carrying out processes of energy production, transport and secretory processes should show the presence of these amino acids. Those organelles are chiefly mitochondria and endoplasmic reticulum. Mitochondria is the powerhouse of the cell and endoplasmic reticulum is the organelle involved in secretion and transport of the molecules. Protein synthesis occurs in the endoplasmic reticulum. The synthesized proteins move from the endoplasmic reticulum and then to lysosomes and are then packaged in vesicles to be transported out of the cell (those that are destined to leave the cell). In the case of the radiolabeled proteins which are destined to leave the cell they will do so fusing with vesicles in the plasma membrane.