pinocytosis
Pinch is temporary Cut is permanent
What happens is that the shell melts off and some parts of the liquid near the membrane get cooked. I do not know how it happens!
When a cell needs to take in a particle larger than the membrane channels can passage, it will invaginate the cell membrane around the particle(s) and pinch off part of the membrane containing the particles inside the cell membrane. This is called phagocytosis (when the particles are primarily solid) or pinocytosis (when the particles are primarily liquid).
A cell performs pinocytosis when it needs a fluid that's outside of the cell. It does this by taking in the fluid particle in through the cell membrane. It wraps the particle in a layer of the membrane. See the related link for an example.
Bodies which pinch off vesicles at end
At pinch off voltage, the channel is blocked at its maximum. (depletion region blocks almost entire channel, so no charge exchange). Therefore, no drain is flown through the channel.
You can pinch off a part of a loaf of bread, yes. So I would use "off" with the word pinch; however, the phrase in the question might be considered a 'colloquialism,' or local slang, as it is.
Pinocytosis
Golgi vesicles are pieces of Golgi membrane that pinch off and carry proteins to other parts of the cell. The vesicle can be thought of as a package to be delivered according to the tag (zipcode) carried by the protein.
If you stick your finger at them they might pinch you....with their claws....
5v