The endoplasmic reticulum is the network or of tiny tubular structures scattered in the cytoplasm. The endoplasmic reticulum is generally of two types smooth and rough endoplasmic reticulum. The rough endoplasmic reticulum has ribosomes attached to it whereas the smooth endoplasmic reticulum does not have ribosomes. The rough ER is generally found in cells actively involved in protein synthesis. Lipid synthesis is associated with the smooth endoplasmic reticulum.
1. It performs the function of packaging the material, delivering them to the target cells and in secretion. Materials to be packaged in the form of vesicles from the ER fuse with the cis face of the golgi apparatus and move towards trans face.
2. A number of proteins synthesised by ribosomes on the endoplasmic reticulum are modified by the golgi bodies before being released
3.Golgi apparatus is the important site of formation of glycoproteins and glycolipids.
Functions of mitochondria are :
1. Mitochondria are the power houses of the cell. they produce cellular energy in form of ATP.
2. They are the sites for aerobic respiration.
3. They possess single circular DNA molecule, RNA, ribosomes and other material for the synthesis of proteins.
1. They help in the digestion of proteins, carbohydrates and lipids as they possess hydrolytic enzmes like proteases, carbohydrases and lipases.
2.Cellular digestion. When a cell dies during the pathological conditions or when a cell grows old due to natural ageing, the lysomes help in the digestion and removal of such cells.