Question

During a pulse-chase experiment, photographic emulsions were prepared at different times during the chase, and radioactive spots were detected at the following times and locations: 5 minutes: rough ER; 10 minutes: Golgi apparatus; 40 minutes: endosomes; 70 minutes: lysosomes; 140 minutes: lysosomes. Which of the following conclusions can be drawn from these results?
A) The proteins were secreted.
B) The proteins traveled from lysosomes to endosomes.
C) The proteins did not travel through the Golgi apparatus.
D) The final destination of the proteins was the lysosome.

Answer 1

Answer:

The correct answer is: D) The final destination of the proteins was the lysosome.

Explanation:

The experiment was used to determine the location of certain proteins, and the results indicate that their last stop was in lysosomes, where they remained for at least 70 minutes.

Lysosomal proteins make up around 60 types of enzymes that are made in the rough endoplasmic reticulum. To reach the lysosomes, these proteins are specifically tagged by the Golgi apparatus with the molecule mannose 6-phosphate.

Lysosomal enzymes have the capacity to break down biomolecules and, to do so, they require an acidic environment.