NEET BIOLOGY

Detailed explanation-1: -The rough ER, which is covered by ribosomes on its outer surface, functions in protein processing. The smooth ER is not associated with ribosomes and is involved in lipid, rather than protein, metabolism.

Detailed explanation-2: -The ribosome that is synthesizing the protein is directly attached to the ER membrane. These membrane-bound ribosomes coat the surface of the ER, creating regions termed rough endoplasmic reticulum, or rough ER (Figure 12-36A).

Detailed explanation-3: -Degradation of cellular material is not a function of endoplasmic reticulum. Degradation of cellular wastes and materials is carried out by lysosomes. Hence statement D is incorrect.

Detailed explanation-4: -So, the correct answer is ‘Have no role in protein synthesis’.

Detailed explanation-5: -The rough endoplasmic reticulum contains ribosomes and makes protein, whereas the smooth endoplasmic reticulum does not contain ribosomes and functions to make lipids and detoxify the cell. Large amounts of smooth ER are found in cells that participate in lipid metabolism and detoxify the body, such as liver cells.