Self-Sustaining Chemical Systems:
The Golgi complex is another
set of folded and nested membranes. At times these membranes are
continuous with the ER and ultimately with the cell surface.
The exact role of the Golgi complex is not clear, but one of its
known functions is to collect proteins, fats, polysaccharides, and
other molecules that have been synthesized on the ER, and package
them into spherical vesicles for storage within the cell or secretion
to the outside.
The pancreatic secretory cell, illustrated at the beginning of the
chapter, synthesizes the precursors of trypsin and chymotrypsin
at its ER, and with the aid of its Golgi complex, secretes these
pre-enzymes into the pancreatic duct for transfer into the digestive
tract and activation into enzymes (see right). The Golgi
complex is a "loading dock" for synthesized molecules, and may have
other functions also.