cytoplasmic cyclin-dependent protein kinase holoenzyme complex
cytoplasmic exosome (RNase complex) +
cytoplasmic microtubule +
cytoplasmic microtubule bundle
cytoplasmic region +
cytoplasmic ribonucleoprotein granule +
cytoplasmic U snRNP body
cytoplasmic ubiquitin ligase complex +
cytoplasmic vesicle +
cytosol +
dense body
ectoplasm
electron transfer flavoprotein complex +
endoplasmic reticulum +
The irregular network of unit membranes, visible only by electron microscopy, that occurs in the cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached).