Question

What is more abundant in S.E.R?
A.Cisternae and vesicles
B.Cisterns and tubules
C.Tubules and vesicles
D.Cisternae

Answer 1

A membrane - bound organelle contained in most eukaryotic cells is a smooth endoplasmic reticulum (smooth ER). It is a part of the endoplasmic reticulum endomembrane system. The production of lipids, steroid hormones, the detoxification of harmful metabolic residues and the processing and metabolism of calcium ions within the cell are its primary features.

Complete step by step answer:
The smooth ER is characterized by a lack of membrane-bound ribosomes from the other portions of the endoplasmic reticulum. Typically made of tubular structures called cisternae, this organelle is also phenotypically distinct. In liver cells that process harmful chemicals, in endocrine cells such as those in the adrenals that produce steroid hormones, and in neural tissue such as neurons and muscle cells that use Ca2 + signalling, Smooth ER is prominent. Tiny, spherical membrane-bound sacs are vesicles, and tubules anchor the endoplasmic reticulum to the persistent membrane-forming nuclear membrane. With new tubules budding off from sides of existing structures, the smooth Endoplasmic reticulum is also a dynamic system. Some tubule branches could also fuse with each other through the aid of GTP hydrolysis.
So, correct answer is option C.

Additional Information:
In the metabolism of lipids, such as cholesterol and triglycerides, that shape all the organism's membranes, the smooth ER is significant. Furthermore, the synthesis and secretion of hormones in the body from cholesterol and other lipid precursors is vital. Besides that, it is important in the metabolism of carbohydrates. For instance, although it contains the enzyme glucose-6-phosphatase, the final reaction of gluconeogenesis happens in the lumen of the smooth ER. The above mentioned enzyme catalyzes the reaction of glucose from glucose-6-phosphate.

Note:
In a range of cellular types (both fauna and flora), smooth endoplasmic reticulum is found and it serves different roles with each one. The smooth endoplasmic reticulum platform allows the action or preservation of key enzymes and the products of these enzymes to be committed to an increased area of the surface. The smooth endoplasmic reticulum is an organelle that is wholly a workhorse for all the rest of the cell to produce proteins and substances.