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

Once an organelle to be destroyed,like a mitochondrion,has been surrounded with a double membrane,what is the name of the structure that has been produced?

The endomembrane system when homogenized is broken up into vesicles,which are heterogeneous but similar in size.These vesicles can be purified and,after purification,often retain their biological activity.They are collectively referred to as _________.

What specific cellular responses are known to be triggered by the regulated release of Ca²⁺ ions from the SER?

What powers the movement of proteins into the mitochondrial matrix?

Where in the Golgi complex does most protein sorting occur?

About what time does PI(4,5)P₂ disappear from a site of endocytosis?

An organelle whose interior exhibits a low pH is identified.It is irregularly shaped and contains acid phosphatase.What is it most likely to be?

What is the effect of CDG1b on cell physiology and what is the treatment that has shown some promise of being effective?

A protein that is normally secreted is genetically engineered by altering the gene that encodes it.The part of the gene encoding the KDEL sequence is removed from the C-terminus and two stop-transfer sequences are inserted in the middle of its gene.When the altered gene is reinserted into the cells,what happens?

In carrying out a pulse-chase experiment,radiolabel appears first over the ER in the basal portion of the cell.It moves next to the Golgi apparatus located centrally.Next,the radiolabel appears in the cell's apical region near a number of small cytoplasmic vesicles.What kind of cell is this?

To what residue of a polypeptide are N-linked oligosaccharide chains attached as that poypeptide enters the RER lumen through the translocon?

A scientist isolates two specific mRNAs.One codes for the enzyme fowlase,an enzyme that is involved in digestion in chickadees;the other codes for the quail enzyme quailase that is involved in cellular carbohydrate metabolism.Both mRNAs are placed in a test tube with RER vesicles stripped of their ribosomes,free ribosomes and precursors for protein synthesis.When the protein synthesis reaction is complete,fowlase is found inside the vesicles;quailase is found in the liquid portion of the test tube outside the vesicles.What can one conclude about the two proteins?

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

Enzymes can be purified from the microsomal fraction.They can then be used as antigens to make antibodies.The antibodies can then be exposed to cells and later visualized in the electron microscope.What allows them to be seen in the electron microscope?

What happens to the breakdown products of materials brought into many single-celled organisms from the extracellular environment?

How is the orientation of membrane proteins in the membrane thought to be accomplished?

What happens to the breakdown products of bacteria brought into mammalian phagocytic cells (like macrophages and neutrophils)from the extracellular environment?

When cells are homogenized,the cytomembrane system is broken into fragments,the ends of which can fuse to form small membranous spheres called ________.

You wish to target a purified enzyme to the lysosomes of macrophages.How might you accomplish this?

CDG1b results from a deficiency in what enzyme?