What is bulk transport?
It is the movement of large solid ( phagocytosis ) or liquid ( pinocytosis ) molecules across the cell surface membrane using energy from respiration.
This includes endocytosis where substances enter the cell by forming an invagination in the cell membrane and eventually a vesicle surrounding the substance. This is an active process and thus requires ATP.
It also includes exocytosis which is the opposite of endocytosis in which the vesicle containing the substance fuses with the cell membrane to release the substance outside the cell. This is also an active process.
Substances that can move via bulk transport are like hormones, polysaccharides, etc.
An example of this is the engulfing of pathogens by phagocytes (endocytosis), then the release of the hydrolysed pieces of the pathogen outside the cell by exocytosis.