Exam 4: The Structure and Function of the Plasma Membrane

Which protein(s)below is(are)thought to be involved in and influence the stability of red blood cell membranes and the cells themselves by imparting strength,elasticity,and pliability to the membrane?

The rate of nerve impulse conduction in two different nerve cell axons differs.The first cell exhibits a rate of conduction substantially higher (about 20 times faster)than the second cell.Both cells have axons of the same diameter.What is a possible explanation for the difference in nerve conduction rate?

You are exploring a rather inhospitable planet,which has seas that are somewhat hydrophobic in nature.Surprisingly,there are living organisms in the seas whose cytoplasm is hydrophobic to a similar degree.These organisms have membranes made primarily of phospholipids arranged in a bilayer.What is the most probable orientation of these phospholipids?

What is the distinguishing characteristic of a P-type pump?

Where in a myelinated axon are nearly all of the ion channels concentrated?

How was the asymmetry of membrane lipids discovered?

What causes the membrane potential to return to the normal negative value after an action potential has occurred?

If Gorter and Grendel,as described in the figure below,extracted lipids from the membranes of red blood cells and determined that they covered 96 mm² of water,what would you estimate as the surface area of the red blood cells from which the lipids were extracted?

Glycolipids have been shown to play roles in certain disease states in humans and other mammals.Which of the situations below illustrate the ways in which this can happen?

What property of membranes allows interactions to take place within the membrane,including the assembly of membrane protein clusters at particular sites and the formation of specialized structures?

They are more gelated and highly ordered than the surrounding more fluid and disordered regions in artificial membranes that consist primarily of phosphoglycerides.They contain higher concentrations of sphingolipids and cholesterol and certain proteins become concentrated within them.What are they?

Which protein in the Question above is likely to be buried within the membrane?

What happens after a subthreshold depolarization?

Why did liposomes not work against diseases as hoped when they were first tried?

The majority of alleles responsible for CF in the United States contain the same genetic alteration,designated DF508.What is the significance of this alteration and how does it lead to CF?

___________ is a process that strengthens certain synapses by repeated neuron stimulation over a short time period.

What are the building blocks of a phosphoglyceride,specifically phosphatidic acid?

In the figure below,N- and O-glycosidic linkages are depicted.Why are these linkages called N- and O-glycosidic linkages?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?