Question

Figure A shows the orientation of the Kiti protein on the membrane of a Golgi-derived vesicle that will fuse with the plasma membrane. Click to view here figures for this exam. Given this diagram, which of the following statements is true? protein inside of a) When this vesicle fuses with the plasma membrane, the N-terminus of Krtl will be in the extracellular space O b) When this vesicle fuses with the plasma membrane, the N-terminus of Krtl will be cytoplasmic c) When this vesicle fuses with the plasma membrane, the entire Krtl protein will be secreted into the extracellular space. o d) When this vesicle fuses with the plasma membrane, the C-terminus of Krtl will be inserted into the

Answer 1

Solution :

Option (a) is correct answer . When this vesicle fuses with the plasma membrane ,the N-terminus Krt1 will be in the extracellular space.

Here the protein membrane with C-terminus which was facing towards the cytosol and the N-terminus is towards the inside of the vesicle. Vesicle fuses with the plasmamembrane and results in orientation changes. Then the protein gets embedded in the plasma membrane at the same time the N-terminus which was present inside the vesicle is placed in the extracellular space whereas the C-terminus in the extracellular side in the vesicle has to be placed in the membrane ( Cytosol side ) .