1) N.J.Kaushikaa2) R.S.Sushmitha3) G.Kayani4) A.Swetha5) Suparna6) S.Bhavani7) Yuvashree8) P.Sonikumari9) Midhilla

Endoplasmic reticulum:

It can be defined as a eukaryotic organelle, which forms a network of tubules, vesicles and cisternaewithin the cells. There are two regions of the Endoplasmic reticulum, which differ in both structure and function. One region is called as rough Endoplasmic reticulum, as it contains ribosome attached to the cytoplasmic side of the membrane and they are the series of flattened sacs. The other region is called as smooth Endoplasmic reticulum as it lacks the attached ribosome and they are tubule network.

Secretory proteins, mostly glycoproteins, are moved across the endoplasmic

reticulum membrane. Proteins that are transported by the endoplasmic

reticulum 5throughout the cell are marked with an address tag called

a signal sequence. The N-terminus (one end) of a polypeptidechain (i.e., a

protein) contains a few amino acids that work as an address tag, which are

removed when the polypeptide reaches its destination. Proteins that are

destined for places outside the endoplasmic reticulum are packed into

transport vesicles and moved along the cytoskeletontoward their destination.

In human fibroblasts, the ER is always co-distributed with microtubules and

the depolymerisation of the latter cause its co-aggregation with

mitochondria, which are also associated with the ER. [17]

PICTURE OF ENDOPLASMIC RETICULUM:

It is mainly responsible for the transportation of proteins and other carbohydrates to another organelle, which includes lysosomes, Golgi apparatus, plasma membrane, etc.They play a vital role in the formation of the skeletal framework.They provide the increased surface area for cellular reactions.They help in the formation of nuclear membrane during cell division.They play a vital role in the synthesis of proteins, lipids, glycogen and other steroids like cholesterol, progesterone, testosterone

Rough ER was mentioned in the section on ribosomes. They are very important in the synthesis and packaging of proteins. Some of those proteins might be used in the cell and some are sent out. The ribosomes are attached to the membrane of the ER. As the ribosome builds the amino acid chain, the chain is pushed into the ER. When the protein is complete, the rough ER pinches off a vesicle. That vesicle, a small membrane bubble, can move to the cell membrane or the Golgi apparatus.

PICTURE OF ROUGH ENDOPLASMIC RETICULUM:

Smooth ER has its purpose in the cell. It acts as a storage organelle. It is important in the creation and storage ofsteroids. It also stores ions in solution that the cell may need at a later time. Steroids are a type of ringed organic molecule used for many purposes in an organism. They are not always about building muscle mass like a weight lifter. The ion storage is important because sometimes a cell needs ions fast. It might not want to search the environment for ions, so it is easier to have them stored in a pack for easy use.

PICTURE OF SMOOTH ENDOPLASMIC RETICULUM:

In plant cell, the endoplasmic reticulum acts as a port for the entry of proteins into the membrane. It also plays a vital role in the biosynthesis and storage of lipids. There are number of soluble membrane, which are associated with the enzymes and the molecular chaperones. The general functions of the endoplasmic reticulum in plant cell are protein synthesis and maturation. Endoplasmic reticulum of plant cell possesses some additional functions, which is not found in animal cells. The additional function involves cell to cell communication between specialized cells and also it serves as a storage site for proteins. Endoplasmic reticulum of plant cell contains enzymes and structural proteins, which are involved in the process of oil body biogenesis and lipid storage. In plants, the endoplasmic reticulum is connected between the cells via the plasmodesmata.

PICTURE OF PLANT CELL WITH ENDOPLASMIC RETICULUM:

In animal cells, the endoplasmic reticulum is a network of sacs, which play a vital role in manufacturing, processing and transporting different types of chemical compounds for use of both inside and outside of the cell. It is connected to the double-layered nuclear envelope, which provides the pipeline between the nucleus and the cytoplasm of a cell.In animal cells, the endoplasmic reticulum is a multifunctional organelle, which synthesis the membrane lipids, proteins and also regulates the intracellular calcium.

PICTURE OF ANIMAL CELL ENDOPLASMIC RETICULUM