explain (E.R) Endoplasmic reticulum ?
Answers
Endoplasmic Reticulum: This is a
complex network of tubes, the lumen of
which is filled with fluid. Two types of
endoplasmic reticula are seen. They are:
Tubes with a smooth surface are called
smooth endoplasmic reticulum. They secrete lipids. Tubes with spherical bodies (ribosomes) attached are known as rough endoplasmic reticulum.
The functions of the endoplasmic reticulum are to form the skeletal framework of the cell, to provide a pathway for the distribution of nuclear material from one cell to the other and to synthesize fats, steroids and cholesterol with the help of enzymes secreted by the cell.
Endoplasmic Reticulum is a network of membraneous tubules present within the cytoplasm of the cell. It starts from the outer nuclear membrane and continues till the periphery of the cell. It is of two types smooth endoplasmic reticulum and rough endoplasmic reticulum. Smooth endoplasmic reticulum don't have ribosomes present on the surface. Rough Endoplasmic reticulum have ribosomes present on the surface.
Smooth endoplasmic reticulum is found in muscle cells and helps in contraction and relaxation of muscles by release and uptake of calcium ions. Rough Endoplasmic reticulum helps in protein synthesis due to the presence of ribosomes