Exam 4: The Structure and Function of the Plasma Membrane

Which site in a neuron receives incoming information from external sources?

A channel that opens in response to changes in ionic charge across a membrane is called a ________.

How do Na⁺ ions enter a neuron when an action potential is initiated?

How is a nerve impulse usually transmitted across a synapse from a presynaptic to a postsynaptic cell?

Diffusion during which the substance to be transported binds selectively to a membrane-spanning protein, which helps the process along, is called ________.

A channel that opens in response to the binding of a specific molecule, which is usually not the solute that passes through the channel is called a ________.

Enzymes which play a role in maintaining cellular integrity by stabilizing membrane fluidity include all of the following EXCEPT:

A procedure in which the gene for an integral membrane protein is altered in such a way that the spatial relationships between some of the amino acids in the protein can be revealed is called ________.

The ability, possessed by all organisms, to respond to external stimulation is known as _______.

When membrane lipids are extracted from cells and used to prepare artificial lipid bilayers, cholesterol and sphingolipids tend to self-assemble into ________ that are more gelated and highly ordered than surrounding regions consisting primarily of _________.

Long-term potentiation is associated with NMDA receptors, one of several types of receptors that bind to the excitatory neurotransmitter __________. Its binding opens an internal cation channel within the receptor that allows __________ influx into the postsynaptic neuron, triggering a cascade of biochemical changes that lead to synaptic strengthening.

Which of the following cell processes depend on the movement of membrane components and would probably not be possible if membranes were rigid, nonfluid structures?

What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface and is covalently linked to a membrane lipid situated within the bilayer?

In the Na⁺/glucose cotransporter, _________ moving down its gradient drives the transport of __________ against its gradient.

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?

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

Which of the following is NOT a potential biological role of the lipid asymmetry of the plasma membrane?

Which part of a neuron conducts impulses away from the cell body toward the target cell(s)?

Why would a transverse diffusion or flip-flop of membrane phospholipids from one leaflet to the other be so rare?

Gorter and Grendel extracted lipids from human red blood cells. They calculated the total surface area for these red blood cell lipids and found it to be 36 µm². How much surface area would these lipids cover once they were spread across the surface of water?