MICROANATOMY

Detailed explanation-1: -These are called membrane bound ribosomes and are firmly attached to the outer cytosolic side of the ER About 13 million ribosomes are present on the RER in the average liver cell. Rough ER is found throughout the cell but the density is higher near the nucleus and the Golgi apparatus.

Detailed explanation-2: -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-3: -Ribosomes are found ‘free’ in the cytoplasm or bound to the endoplasmic reticulum (ER) to form rough ER. In a mammalian cell there can be as many as 10 million ribosomes. Several ribosomes can be attached to the same mRNA strand, this structure is called a polysome. Ribosomes have only a temporary existence.

Detailed explanation-4: -Ribosomes are found free in the cytoplasm or on the surface of rough endoplasmic reticulum. They may exist singly or form chains (polyribosomes). Ribosomes serve as the site of protein synthesis. This is accomplished with transfer RNA (tRNA) for amino acid transport to the ribosome, and specific mRNA molecules.