What happens during vesicle fusion with target membranes?

During vesicle fusion with target membranes, the lipid bilayers of the vesicle and the target membrane merge, a process that is crucial for the release of the contents of the vesicle into the target compartment. This fusion involves specific proteins called SNAREs that facilitate the docking and merging of the membranes. When vesicle fusion occurs, the bilayers come into close proximity and form a continuous membrane structure. As a result, the contents of the vesicle, which can include proteins, hormones, or neurotransmitters, are released into the target area, allowing for various cellular functions like secretion, signal transduction, or membrane recycling to take place.

In contrast, other options fail to describe the actual process of vesicle fusion accurately. The idea that the vesicle disintegrates might suggest a complete breakdown without functional release, which does not capture the essence of how vesicle fusion works. Retaining the contents within the vesicle contradicts the purpose of vesicle fusion, as the process is intended for secretion and interaction. Lastly, the concept of the vesicle remaining dormant does not occur in the context of fusion; dormancy would imply inactivity, while fusion is an active process essential for cellular communication and metabolism.