In eukaryotic
cells, a network of tubular structures
are found in cytoplasm i.e. endoplasmic reticulum. Endoplasmic reticulum is
found connected to the outer nuclear membrane.
The endoplasmic reticulum are of two type.
Rough Endoplasmic Reticulum- This endoplasmic reticulum is attached to the
outer nuclear membrane .Ribosomes are attached on the surface of these
endoplasmic reticulum. RER are associated with protein synthesis and packaging.
Smooth endoplasmic reticulum- These
endoplasmic reticulum are without
ribosomes . These are associated with synthesis and storage of lipid.
In the endoplasmic reticulum following
three components are found-
Cisternae- These are long ,flattened,
unbranched and paralle arranged tubules .
Tubules –These
are small ,smooth- walled branched tubular structures.
Vesicles
– These are rounded sac like structures.
Sarcoplasmic
reticulum is the modification of endoplasmic reticulum and found in the muscle
fibre .
Functions-
·
The endoplasmic reticulum rovide
mechanical strength to the cytoplasm and cell.
·
The endoplasmic reticulum involves in synthesis
of proteins and lipid.
·
The smooth endoplasmic reticulum also
involves in synthesis of glycogen in cells of liver.
