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 rough endoplasmic reticulum (RER) is so named for the appearance of its outer surface, which is studded with protein-synthesizing particles known as ribosomes.

Detailed explanation-3: -The secretory proteins are synthesized on ribosomes attached to Endoplasmic Reticulum. These proteins enter the lumen of RER and then through vesicles are passed on to Golgi apparatus. In Golgi apparatus, proteins undergo post translational modification like glycosylation, addition of signal peptide etc.

Detailed explanation-4: -Secretory proteins are synthesized on ribosomes bound to the membrane of the endoplasmic reticulum (ER).

Detailed explanation-5: -The two types of ER often appear as if separate, but they are sub-compartments of the same organelle. Cells specialising in the production of proteins will tend to have a larger amount of rough ER whilst cells producing lipids (fats) and steroid hormones will have a greater amount of smooth ER.