The endoplasmic reticulum was discovered in 1945 by researchers Ernest Fullman, Keith Porter and Albert Claude. The endoplasmic reticulum is separated into two categories. The parts of the organelle with ribosomes on the surface are called rough and areas without ribosomes are smooth.
The rough portion of the endoplasmic reticulum manages the synthesis of proteins and packages them into vesicles for transport and further modification by the golgi apparatus. Due to its close proximity to the nuclear envelope, the endoplasmic reticulum allows ribosomes to translate mRNA from the nucleus into proteins. The endoplasmic reticulum is essential for proper cell function. It is found in all cells requiring proteins and enzymes.