Question

Insulin is a protein that is produced by certain pancreatic cells and secreted into the bloodstrecam. (This is true.) Which of the following choices best describes the route of insulin from its production to ins exit from the cell:_______.1. rough ER, transport vesicles, cell membrane 2. rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane 3. rough ER, lysosomes, transport vesicles, cell membrane 4. rough ER, Golgi apparatus, smooth ER, cell membrane

Answer 1

Answer:

2) rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane

Explanation:

Insulin is a peptide hormone secreted by the pancreatic cells which are considered as the endocrine gland. Since the insulin is a peptide hormone, therefore, it follows the same path of secretion as other peptides follow.

The insulin peptide is produced by the ribosomes present on the endoplasmic reticulum. The insulin thus has to undergo certain modifications so the peptide is packaged in the transport vesicle and reaches the cis face of the Golgi apparatus.

There the peptide is modified and from there again packaged into the transport vesicles. The transport vesicles than reaches the cell membrane and fuse with the cell membrane and then released into the blood by exocytosis.

Thus, Option-2 is correct.