Final answer:
Vesicles use receptor proteins and SNARE interactions to ensure accurate delivery of their contents to the appropriate target membrane, utilizing mechanisms like receptor-mediated endocytosis to bring substances into the cell.
Step-by-step explanation:
Vesicles are selectively targeted to their target membrane through the interaction between protein markers and SNARE proteins. Vesicles carrying cargo proteins have receptor proteins that are recognized by clathrin and COP proteins, facilitating their budding. Each vesicle is equipped with V-SNARE proteins on its membrane. Upon reaching the target membrane, which contains complementary T-SNARE proteins, the V-SNARE and T-SNARE proteins bind. This protein-protein interaction ensures the precise docking and eventual fusion of the vesicle with the target membrane, leading to the delivery of the vesicle's contents to the correct location.
As an example, in receptor-mediated endocytosis, the uptake of substances is targeted to specific substances that bind to receptors on the external cell membrane. This triggers aggregation of receptors in coated pits, leading to the formation of a coated vesicle that brings substances into the cell.
Vesicles can originate from different locations such as the endoplasmic reticulum or Golgi apparatus and can have varied destinations, including other organelles within the cell or the extracellular space.