GENERAL HISTOLOGY

Detailed explanation-1: -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-2: -Proteins are assembled at organelles called ribosomes. When proteins are destined to be part of the cell membrane or exported from the cell, the ribosomes assembling them attach to the endoplasmic reticulum, giving it a rough appearance.

Detailed explanation-3: -The rough endoplasmic reticulum is different from the smooth endoplasmic reticulum. 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.

Detailed explanation-4: -endoplasmic reticulum: A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.