Video Transcript
A diagram outlining the basic
structure of a eukaryotic cell is provided, with the major organelles labeled. What is the function of the rough
endoplasmic reticulum? (A) The rough ER synthesizes,
stores, and transports lipids and carbohydrates within the cell. (B) The rough ER provides the site
for the aerobic stages of respiration. (C) The rough ER is covered with
ribosomes that are the site of protein synthesis. Or (D) the rough ER transports
modified proteins and lipids to the cell membrane.
The rough endoplasmic reticulum,
sometimes simply referred to as the rough ER or RER, is a membrane-bound organelle
found in eukaryotic cells that is located close to the nucleus. Let’s discuss the different answer
options to determine which one correctly describes the function of this
structure.
The site of aerobic respiration is
the mitochondrion, not the rough ER. This means that we can eliminate
answer choice (B).
The smooth endoplasmic reticulum,
sometimes referred to as the smooth ER or SER, plays the role of synthesizing
lipids. These lipids are then transported
to the Golgi apparatus, which packages and delivers lipids, proteins, and other
chemicals throughout the cell and to the cell membrane. Neither of these functions is
accomplished by the rough ER, so we can eliminate answers (A) and (D) as well.
The membrane of the rough ER is
studded with ribosomes, giving it the rough appearance from which it gets its
name. Ribosomes are the site of protein
synthesis. This means that we have found the
function of the rough ER and therefore the correct answer to this question. The correct answer is (C). The rough ER is covered with
ribosomes that are the site of protein synthesis.
