Question

Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse?
A. Golgi apparatus
B. Secretory vesicles
C. Exterior of the cell
D. Rough ER

Answer 1

Answer:

Option-C

Explanation:

A pulse-chase experiment which is used to study the cellular process taking place in the cells. This uses the labelled molecule which is incorporated into the cellular pathway and then the unlabeled molecules are used over time to determine how much time is required by the unlabeled molecule to replace the labelled molecule.

In the given question, the pancreatic cell which secretes the digestive enzyme known as the acinar cell is labelled with the leucine and then used unlabeled leucine.

When observed after three hours, the black spots will appear on the exterior of the cell as the protein has been synthesised by the ER and now has been secreted from the cell.

Thus, Option-C is the correct answer.