Question 12
The proteins and lipids, essential for building the cell membrane, are manufactured by
(a) Rough endoplasmic reticulum
(b) Golgi apparatus
(c) Plasma membrane
(d) Mitochondria
(a) Rough endoplasmic reticulum
Endoplasm is the inner part of a cell's cytoplasm. Reticulum means a fine network. So, endoplasmic reticulum is an interlinked network of cisternae (membrane disks), vesicles (intracellular transport sacs) and tubules inside a eukaryotic cell.
The rough endoplasmic reticulum (rough ER) is a part of the endomembrane system of the cell and a subset of the endoplasmic reticulum (ER). This organelle is primarily concerned with the synthesis, folding and modification of proteins, especially those that need to be delivered to different organelles within the cell or secreted from the cell. The rough ER is also involved in the response of the cell to unfolded proteins.
Proteins and lipids formed by ER help in building the cell membrane. This process is known as membrane biogenesis. Membrane biogenesis is the process which involves the synthesis of cell membrane with the help of proteins and lipids.