Question

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________ Group of answer choices in the smooth endoplasmic reticulum in the rough endoplasmic reticulum on the free ribosomes in the plasma membrane in the ribosomes of the mitochondria

Answer 1

Proteins that function in the plasma membrane of a cell are likely synthesized in the rough endoplasmic reticulum (RER) and then undergo further modification in the Golgi apparatus before becoming integral membrane proteins.

Step-by-step explanation:

Proteins that ultimately function in the plasma membrane of a cell are most likely to have been synthesized in the rough endoplasmic reticulum (RER).

The RER is responsible for synthesizing membrane and secretory proteins. Ribosomes on the surface of the RER produce proteins that are destined for the cell membrane.

After synthesis, these proteins are transported to the Golgi apparatus for further modification before being packaged into vesicles and ultimately becoming integral membrane proteins of the plasma membrane.

Answer 2

The correct answer is: in the rough endoplasmic reticulum.

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized in the rough endoplasmic reticulum.

Step-by-step explanation:

The endoplasmic reticulum constitutes a system of membrane-limited cavities (cisterns). There are two different forms of endoplasmic reticulum: rough and smooth, which have a different appearance and structure. The rough endoplasmic reticulum appears in many cells as a set of cisternae stacked in parallel. Its membranes are associated with ribosomes, its main function is to synthesize proteins with ribosomes attached to its membrane. The synthesized proteins pass from the rough endoplasmic reticulum to the smooth endoplasmic reticulum, then to the Golgi apparatus and from there, to the lysosomes, to the plasma membrane or to the exterior. Before being transported to other cytoplasmic organelles (Golgi apparatus, lysosomes), to the plasma membrane or to the exterior of the cell, they must be glycosylated to become glycoproteins.