CBSE Class 11-science Answered

A major function of cisternae is modifying, sorting and packaging of proteins for secretion. It is also involved in the transport of lipids around the cell, and the creation of lysosomes. 60S subunit has a molecular weight which is almost double that of 40S subunit. It also produces approximately 49 proteins as compared to that of 33 proteins produced by 40S subunit. Since the protein production is more in 60S subunit as compared to 40S subunit, the processes of modifying, sorting and packaging of proteins is also comparatively on a larger scale in 60S subunit than 40S subunit. Hence, to assist this function, cisternae are associated with 60s subunit and not with 40 S ribosome.