The largest single membrane bound intracellular compartment is -

The largest single membrane-bound intracellular compartment in eukaryotic cells is the endoplasmic reticulum (ER). The ER is a series of flattened sacs and tubules that extend throughout the cytoplasm. It has two main types: rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER), which perform various functions in the cell. The RER is studded with ribosomes and involved in protein synthesis, while the SER is involved in lipid synthesis, calcium storage, and detoxification of drugs and poisons.