Final answer:
The vesicles that transport proteins from the Golgi to lysosomes and endosomes are initially coated with clathrin, which is crucial for vesicle formation and subsequent fusion with target organelles. option 1 is the correct answer.
Step-by-step explanation:
The vesicles that carry proteins from the Golgi to lysosomes and endosomes are initially coated with a protein known as clathrin.
This coating helps in the formation of vesicles through processes such as budding off from the Golgi apparatus. Once the vesicle has been formed, the clathrin coat is lost, allowing the vesicle to fuse with its target organelle like endosomes or lysosomes.
Interestingly, clathrin is also involved in the formation of vesicles during receptor-mediated endocytosis, where substances outside the cell bind to receptors and are internalized when clathrin-coated pits invaginate and form clathrin-coated vesicles. Receptor-mediated endocytosis is a major pathway for the uptake of specific molecules into the cell, depending on their affinity to certain receptors.