AP BIOLOGY

Detailed explanation-1: -endoplasmic reticulum (ER), in biology, a continuous membrane system that forms a series of flattened sacs within the cytoplasm of eukaryotic cells and serves multiple functions, being important particularly in the synthesis, folding, modification, and transport of proteins .

Detailed explanation-2: -The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.

Detailed explanation-3: -Membrane-bound ribosomes, attached to the cytosolic side of the ER membrane, are engaged in the synthesis of proteins that are being concurrently translocated into the ER.

Detailed explanation-4: -The endoplasmic reticulum (ER) is a dynamic organelle responsible for many cellular functions, including the synthesis of proteins and lipids, and regulation of intracellular calcium levels.

Detailed explanation-5: -The ribosomes recognize ER localization sequences in the mRNA they read and then dock on the rough ER. The ribosomes then use the large surface area of the rough ER to produce proteins into the membrane or the lumen.