Question

Function of R.E.R. is
A. Autolysis
B. Lipid synthesis
C. Protein synthesis
D. Carbohydrates synthesis

Answer 1

Hint: Endoplasmic reticulum is of two types: smooth endoplasmic reticulum (SER) and rough endoplasmic reticulum (RER). The rough endoplasmic reticulum has attached ribosomes present on it.

Complete answer:
RER and SER have one main difference that is the presence of ribosomes on the rough endoplasmic reticulum. Because of attached ribosomes their functions also vary. Ribosomes produce, secrete, and export proteins.

> Option A - Autolysis is known as self digestion of the cell by action of its own enzymes on it. This process is initiated by lysosomes cells, they secrete some enzymes that activate this process and the cell starts digesting itself.

> Option B - Lipid synthesis takes place in smooth endoplasmic reticulum with golgi bodies not the rough endoplasmic reticulum. The endomembrane compartment is a major site of lipid synthesis.

> Option C- Ribosomes is the site of protein synthesis in a cell. Rough has ribosomes attached to it so the function of the rough endoplasmic reticulum (RER) is protein synthesis.

> Option D - This process of carbohydrate synthesis takes place in the endoplasmic reticulum but they are modified to complex molecules in the golgi bodies. Many new monomers are added to it to make it form more complex.

Hence, the correct answer is option (C).

Note: The process of protein synthesis occurs in two phases transcription and translocation. There is first activation of the amino acids then the process of transfer of amino acids to tRNA. After that initiation of polypeptide chain and then chain termination and then protein translocation takes place. These are main steps in the synthesis of proteins.