#Question id: 2243
#Unit 2. Cellular Organization
Features of the fluid mosaic model of membrane structure include:
A. a lipid bilayer.
B. dynamic motion of both membrane lipids and proteins.
C. proteins that may either rest on the surface or penetrate the membrane.
D. the hydrophobic core of the bilayer prevents the unassisted movement of water-soluble substances from one side to the other.
E. Covalent interactions between phospholipids, and between phospholipids and proteins, lend strength and resilience to the membrane.
Which of the following is correct?
#Question id: 2244
#Unit 2. Cellular Organization
Arrange the statements below in the proper sequence of events that occur in an action potential:
I. The resting potential is re-established.
II. A stimulus depolarizes the membrane to threshold.
III. Na+ gates open and Na+ rushes into the cell.
IV. K+ gates open and K+ rushes out of the cell.
#Question id: 2245
#Unit 2. Cellular Organization
Which of these statements is generally true of integral membrane proteins?
#Question id: 2246
#Unit 2. Cellular Organization
Which of the following statements describe(s) the typical biomembrane?
a. It may include different types of lipid molecules.
b. The lipid molecules in the membrane are attached to each other though covalent bonds.
c. All lipids and proteins in the biomembrane are equally mobile.
d. It contains a hydrophilic core.
e. It has a cytosolic face and an exoplasmic face.
#Question id: 2247
#Unit 2. Cellular Organization
When computing the osmotic pressure that must be placed across the membrane to stop the flow of water, what is the glucose osmotic equivalent of 1 M CaCl2?
#Question id: 2248
#Unit 2. Cellular Organization
The movement of Na+ ions into an animal cell
a. has a positive ΔG value.
b. is energetically favorable.
c. is chemically favorable.
d. drives the export of Ca2+ in muscle cells.