Question

you were able to radioactively tag and thereby trace an amino acid that is used to make insulin, a hormone that will be exported out of the cell. the pathway of the tagged amino acid would be ____________. multiple choice free ribosome → cytosol → vesicle → extracellular fluid rough er → golgi complex → golgi vesicle → extracellular fluid rough er → smooth er → golgi complex → golgi vesicle → extracellular fluid smooth er → golgi complex → golgi vesicle → extracellular fluid smooth er → golgi complex → lysosome → extracellular fluid

Explanation:

Insulin is a secreted protein. Secreted - protein synthesis starts on ribosomes attached to the rough endoplasmic reticulum (rough ER). Then, the protein is transported to the Golgi complex for modification and packaging into Golgi vesicles. Finally, the Golgi vesicles fuse with the plasma membrane and release the protein into the extracellular fluid.

Answer:

B. rough ER → Golgi complex → Golgi vesicle → extracellular fluid