Question

You are given a liver cell line that secretes albumin proteins and takes in transferrin proteins. You are interested in visualizing this process using TEM. To visualize these proteins, you used 18nm gold tagged antibodies against albumin proteins and tagged transferrin proteins with 12nm gold particles.

A) (1.5pt) Using this experimental set up, how can you identify which vesicles are part of the exocytic pathways vs endocytic pathway? Explain what your results would look like. (5 sentence max)

B) (1.5pt) After you analyzed your results, you noticed some vesicles were not coated with clathrin. Explain why. (4 sentence max)

Please be very detailed so I can understand. Thank you!

Answer 1

A) The vesicles containing the 18nm gold tagged antibodies (against albumin proteins) are a part of the exocytotic pathway, while the vesicles containing the 12nm gold tagged antibodies (against transferrin) are a part of the endocytotic pathway.

The vesicles containing 18nm gold tagged antibodies will appear dense and darker than the vesicle containing the 12 nm gold tagged antibodies.

B) Some of the vesicles are not coated with clathrin as they transport the proteins that do not require clathrin, such as grwoth factors, and transporters.