Question

Are cisternae connected?

Answer 1

Hint: Golgi apparatus, also known as Golgi complex or Golgi body, a membrane-bound organelle of eukaryotic cells (cells with a clearly defined nucleus) consisting of a series of flattened, stacked pouches called cisterns.

Complete answer:
 The cisternae is a flattened membrane vesicle of the endoplasmic reticulum and the Golgi apparatus. A Golgi stack may contain from three to twenty cisterns, but most contain about six cisterns. Golgi cisternae can be divided into four classes: cis, medial, trans, and TGN.

Each type of cistern contains different enzymes to prevent enzymatic activity from being redundant. Almost all of the cisterns in the Golgi apparatus exhibit multiple stacking. However, there are evolutionary lines in which the stacked characteristics have been lost.

Cisternae packs and modifies proteins and polysaccharides. Biosynthetic cargo proteins travel through cisterns and undergo remodeling of glycans and other modifications. Cisternae packs the proteins and then sends them to the transport carrier. They are also packing polysaccharides that are synthesized in the Golgi apparatus. The compounds enter a stack on the cis-side of the Golgi and exit the trans-side where most of the packaging occurs.

The functions of the cistern change as it undergoes micro maturation. The immature cisterns receive the COPII vesicles from the endoplasmic reticulum. New cisterns can be produced during this stage. The next stage begins when carbohydrate cisterns swap material through COPI vesicles. This occurs when glycosylation and polysaccharide synthesis occur. Mature cisterns reach the final stage the where cargo proteins are sent to transport carriers and finally the cisternae disassemble.

Thus, Cisternae, especially those found in Golgi bodies, show multiple stacking. These cisterns are connected to the endoplasmic reticulum.

Note: The cisternal maturation model indicates that the cis cisternae move forward and mature into the trans cisternae, with the new cis cisternae forming from the fusion of the cis-face vesicles. Vesicles are formed in this model but are used only to transport molecules back to the endoplasmic reticulum.