<P> The general structure of the endoplasmic reticulum is a network of membranes called cisternae . These sac - like structures are held together by the cytoskeleton . The phospholipid membrane encloses the cisternal space ( or lumen ) , which is continuous with the perinuclear space but separate from the cytosol . The functions of the endoplasmic reticulum can be summarized as the synthesis and export of proteins and membrane lipids , but varies between ER and cell type and cell function . The quantity of both rough and smooth endoplasmic reticulum in a cell can slowly interchange from one type to the other , depending on the changing metabolic activities of the cell . Transformation can include embedding of new proteins in membrane as well as structural changes . Changes in protein content may occur without noticeable structural changes . </P>
<P> The general structure of the endoplasmic reticulum is a network of membranes called cisternae . These sac - like structures are held together by the cytoskeleton . The phospholipid membrane encloses the cisternal space ( or lumen ) , which is continuous with the perinuclear space but separate from the cytosol . The functions of the endoplasmic reticulum can be summarized as the synthesis and export of proteins and membrane lipids , but varies between ER and cell type and cell function . The quantity of both rough and smooth endoplasmic reticulum in a cell can slowly interchange from one type to the other , depending on the changing metabolic activities of the cell . Transformation can include embedding of new proteins in membrane as well as structural changes . Changes in protein content may occur without noticeable structural changes . </P>
what describes a function of the endoplasmic reticulum within a cell
what describes a function of the endoplasmic reticulum within a cell
synthesis and export of proteins and membrane lipids , but varies between ER and cell type and cell function
synthesis and export of proteins and membrane lipids , but varies between ER and cell type and cell function