Structure
The general structure of the endoplasmic reticulum is a membranous network of cisterns(sac-like structures) held together by the cytoskeleton. The phospholipid membrane encloses a space, the cisternal space (or lumen), which is continuous with the perinuclear space but separate from the cytosol. The functions of the endoplasmic reticulum vary greatly depending on its cell type, cell function, and cell needs. The ER can even modify to change over time in response to cell needs. The three most common varieties are called rough endoplasmic reticulum, smooth endoplasmic reticulum, and sarcoplasmic reticulum.
The quantity of RER and SER in a cell can slowly interchange from one type to the other, depending on changing metabolic needs. Transformation can include embedment of new proteins in membrane as well as structural changes. Massive changes may also occur in protein content without noticeable structural changes.
Read more about this topic: Smooth Endoplasmatic Recticulum
Famous quotes containing the word structure:
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—C. Northcote Parkinson (1909–1993)
“When a house is tottering to its fall,
The strain lies heaviest on the weakest part,
One tiny crack throughout the structure spreads,
And its own weight soon brings it toppling down.”
—Ovid (Publius Ovidius Naso)
“The structure was designed by an old sea captain who believed that the world would end in a flood. He built a home in the traditional shape of the Ark, inverted, with the roof forming the hull of the proposed vessel. The builder expected that the deluge would cause the house to topple and then reverse itself, floating away on its roof until it should land on some new Ararat.”
—For the State of New Jersey, U.S. public relief program (1935-1943)