Liver cells are exposed to radioactive amino acids; all proteins synthesized during this time are radioactive. the cells are then re moved at 5-minute intervals and fractionated. where in the cells is the radioactively labeled enzyme lipase performing its intracellular functions?
a. in lysosomes
b. on ribosomes
c. in the cytoskeleton
d. in the endoplasmic reticulum
e. in the golgi i know that the answer is in the er, but why wouldn't it be in the ribosomes if that is where proteins are synthesized.

The Radioactively labeled enzyme, lipase performs its function in the endoplasmic reticulum

Explanation:

Lipase is found in the Endoplasmic reticulum (ER), because

- it helps in the breakdown of lipids into fatty acids, and the ER is an organelle of liver cell, known to aid the intracellular transport of materials within the cytoplasm.

Therefore, since lipid stored or transported into liver will be distributed by ER, the radioactive Lipase is usually present to breakdown the lipids for easy transport and usage by other cell organelles.