Ans. d (All of the above). (Ref. Human Histology by JB Singh, 3rd ed., p 17) GOLGI APPARATUS # It is a membrane-bound structure with a single membrane. # It is actually a stack of membrane-bound vesicles that are important in packaging macromolecules for transport elsewhere in the cell. # The enzymatic or hormonal contents of lysosomes, peroxisomes and secretory vesicles are packaged in membrane- bound vesicles at the periphery of the Golgi apparatus. # The Golgi apparatus is a cell structure mainly devoted to processing the proteins synthesized in the endoplasmic reticulum (ER). Other proteins moving through the Golgi will end up in lysosomes or be secreted by exocytosis (e.g., digestive enzymes). # The major processing activity is glycosylation: the adding of sugar molecules to form glycoproteins. # In some cells, e.g., mucus-secreting cells in epithelia, the amount of carbohydrate so far exceeds that of the protein that the product is called a mucopolysaccharide (also known as a proteoglycan). # Small peptides, e.g., some hormones and Neurotransmitters, are too small to be synthesized directly by ribosomes. # Instead, the ribosomes on the ER synthesize a large precursor protein that is later cut up into small peptide fragments as it traverses the Golgi E. g.: proopiomelanocortin (POMC) -- a polypeptide of 265 amino acids from which is cut ACTH, alpha and beta MSH, beta-endorphin and others. # The Golgi consists of a stack of membrane-bounded cisternae located between the endoplasmic reticulum and the cell surface. # So there are mechanisms to sort out the processed proteins and send them on to their destinations while reclaiming processing proteins (e.g., glycosylases) for reuse.Q