Body Double

DNA is not the only “double helix” in living cells. The protein factory of cells, endoplasmic reticulum, also has a double helical structure. It resembles a parking lot with helical ramps joining different levels. This optimises packaging, maximising the number of ribosomes, that perform protein synthesis in the endoplasmic reticulum. This may lead to new insights into the functioning of this important organelle. 

Source

Down To Earth, August, 2013