You are investigating the lateral mobility of integral membrane proteins in the

Question

You are investigating the lateral mobility of integral membrane proteins in the plasma membrane of Bloggs cells. You have at your disposal specific antibodies against the extracellular domain of 2 different membrane proteins, Bloggs1 and Bloggs2. You first try a "FRAP" (fluorescence recovery after photobleaching) experiment. You covalently attach a green fluorescent label onto an antibody against Bloggs1 (anti-Bloggs1) and a red fluorescent label onto anti-Bloggs2. You add these to Bloggs cells growing in culture, and you can see both green fluorescence and red fluorescence distributed over the whole surface of each cell. You then bleach both the red and green fluorescence in one spot using a tightly focused laser beam and follow the recovery of each color of fluorescence in that spot over time. You see a pattern like this in cell after cell: Anti-Bloggs1 Anti-Bloggs2 TIME after photobleaching Based on this experiment, which protein, Bloggs1 or Bloggs2, diffuses more quickly in the plane of the bilayer? O Bloggs1 O Bloggs2 Submit Answer Tries 0/1

Explanation / Answer

1) Bloggs 1 diffuses faster than Bloggs2 . This is evident from the slope of the tangent to curve for bloggs1 and Bloggs2 . At any point of time it is steeper than that for Bloggs 2. The fluorescence for bloggs1 reaches it Maxima (original fluorescence) earlier than Bloggs2 does.

2) bead B. This is so because Bloggs 1 protein diffuses fast and hence in a sec it would travel longer distances which is what happenes in the trace by bead B.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.