The main organelle involved in modification and routing of newly synthesized proteins to their destinatoins is

Options

A. chloroplast
B. mitochondria
C. lysosome
D. endoplasmic reticulum

Answer

D

Explanation

Porter coined the name Endoplasmic Reticulum (ER). It is a network of tubules, vesicles andcisternae within an eukaryotic cell (absent inprokaryotic cells). Two types of ER are recognisedon the basis of presence/absence of ribosomes on the wall of the ER.
(i) Smooth ER It does not have ribosomes. Smooth ER helps in the synthesis of lipid and glycogen.
(ii) Rough ER Wall of this ER contains ribosomes.Rough ER is involved in protein synthesis andtransfer.
Protein synthesis takes place in ribosomes attachedon wall of ER. Newly formed protein enters withinthe cavity of rough ER and follows following path : Protein `to` Cavity of rough ER `to` Cavity of smoothER `to` Golgi membrane `to` Lysosomes or transport vesicles or secretory granules.