BOTANY

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: -The ER can be classified in two functionally distinct forms: smooth endoplasmic reticulum (SER) and rough endoplasmic reticulum (RER). The morphological distinction between the two is the presence of protein-synthesizing particles, called ribosomes, attached to the outer surface of the RER.

Detailed explanation-3: -ROUGH ENDOPLASMIC RETICULUM 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.

Detailed explanation-4: -Ribosomes on RER, which give RER its rough appearance, specialize in the synthesis of proteins that possess a signal sequence that directs them specifically to the ER for processing. Proteins synthesized by the RER have specific final destinations, such as the cell membrane, cell exterior, or the ER itself.

Detailed explanation-5: -It primarily has a catalytic function and it binds with the aminoacylated tRNAs. These ribosomes constantly attach and detach from the endoplasmic reticulum as they are not a part of a stable organelle. They attach when the ribosome begins to synthesize proteins that are going to be secreted.