Exam 8: Cytoplasmic Membrane Systems: Structure, Function, and Membrane Trafficking

What GTP-binding protein plays a regulatory role by initiating vesicle formation and by regulating the assembly of the vesicle's COPII coat?

How many subcompartments are there in chloroplasts into which proteins can be delivered?

Which of the following is a function associated with the smooth endoplasmic reticulum in at least some cells?

What happens to a newly synthesized glycoprotein after the binding of calnexin or calreticulin to help the protein correctly complete its folding?

An infant,who is unable to acquire antibodies properly from his mother's breast milk,is born.Tests determine that he makes receptors for the antibodies and that they efficiently bind the antibodies,yet they are not exactly like normal receptors.What is a possible explanation for the inability to take up the antibodies.

Which of the following organelles imports proteins in their native,folded conformation?

You have isolated from a cell vesicles that are shown to be derived from the Golgi apparatus.They take up a large amount of osmium tetroxide when stained and contain little nucleotide diphosphatase activity.These vesicles also contain a few proteins typical of the endoplasmic reticulum.Is it possible to determine where in the Golgi body these vesicles originated? Explain your answer.

Cells are infected with a virus carrying a temperature-sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restrictive temperatures.Thus,at higher temperatures,______________.

Where does the PTS receptor bind to peroxisome-destined proteins?

The phosphorylated rings of phosphoinositides are recognized and bound by particular proteins.Where are the phosphorylated rings located?

The three-legged assembly of protein chains that makes up a clathrin molecule and that can assemble into a network of polygons resembling a honeycomb is called a(n)_____.

What is responsible for the deficiency in I-cell disease patients in which the lysosomal enzymes do not carry the normal mannose phosphate residues that target them to lysosomes?

Why are yeast cells often used to study eukaryotic gene mutations affecting secretion and other cytomembrane processes?

The coat of vesicles that transport materials around the cell interior ___________.

What would happen to the movement of vesicles toward their eventual target if a microtubule inhibitor like colchicine were added to the cells?

What drives the engulfment of particulate material by phagocytosis?

What allows smooth and rough vesicles (microsomes)to be readily separated by density gradient centrifugation?

What determines the sequence of sugar addition to glycoproteins traveling through the Golgi complex?

The oligosaccharide block that is added to secretory proteins after they enter the ER lumen goes through a number of modifications after its attachment.What is the first modification that occurs?

SNAREs vary in structure quite a bit,but all of them contain a common domain.Where is this domain located,of what is it composed and what is it called?