Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 3

Biosynthesis of Integral Membrane Proteins. In addition to their role in cellular secretion, the rough ER and the Golgi complex are also responsible for the biosynthesis of integral membrane proteins. More specifically, these organelles are the source of glycoproteins commonly found in the outer phospholipid monolayer of the plasma membrane.
(a)In a series of diagrams, depict the synthesis and glycosylation of glycoproteins of the plasma membrane.
(b)Explain why the carbohydrate groups of membrane glycoproteins are always found on the outer surface of the plasma membrane.
(c)What assumptions did you make about biological membranes in order to draw the diagrams in part a and answer the question in part b