Final answer:
Vesicles fuse with the membrane of their target location or organelle through a process involving the binding of complementary V-SNARE and T-SNARE proteins, which leads to membrane fusion and contents release via exocytosis.
Step-by-step explanation:
How does a vesicle fuse with the membrane of the target organelle or location? For this process, transport vesicles often depart from the endoplasmic reticulum (ER) and move towards the Golgi apparatus, specifically fusing with its cis face. The vesicles empty their contents into the Golgi apparatus where proteins and lipids undergo modifications such as the addition of sugar molecules or other tags. After processing, they are packaged into new vesicles that bud off from the apparatus's trans face.
These vesicles can be classified either as transport vesicles or secretory vesicles, based on their contents and final destinations. The transport vesicles may fuse with other organelles within the cell while secretory vesicles may bind with the plasma membrane. Before fusion, secretory vesicles typically enlarge by fusing with each other. When a signal triggers the release of their contents, they fuse with the plasma membrane in a process known as exocytosis. This involves the binding of V-SNARE proteins on vesicles to complementary T-SNARE proteins on the plasma membrane, effectively leading to the merging of vesicle and membrane, and thereby releasing the vesicle's contents to the exterior of the cell or into the target organelle.