3. In an aqueous environment, the phospholipids of a membrane____.
a) are arranged in a single layer
b) are arranged in a bilayer with the polar heads of each layerlocated at the surface
c) are arranged in a bilayer with the fatty acid tails locatedat the surface
d) are arranged in a bilayer but the phospholipids have nospecific orientation
e) dissolve
4. which of the following molecules demonstrate dual solubilitycharacteristics
a) sterols only
b) proteins only
c) phospholipids only
d) sterols and phospholipids
e) sterols, phospholipids, and proteins
5. The "mosaic" part of the fluid mosaic model refers to themembrane ____.
a) proteins
b) phospholipids
c) cholesterol
d) functions
e) layers
9. Transport of a molecule across a cell membrane by facilitateddiffusion ____.
a) does not exhibit specificity for a particular type ofmolecule
b) requires the input of energy
c) depends on a concentration gradient
d) goes against the concentration gradient
e) allows non-polar uncharged molecules to diffuse across amembrane
13. A transport system in which transport of an ion in onedirection provides the energy for active transport in the oppositedirection is known as ____.
a) primary active transport
b) active diffusion
c) secondary active transport
d) cotransport
e) osmosis
14. Cells undergo exocytosis ____.
a) to pump protons down a concentration gradient
b) when replicating
c) to secrete protein and wastes from the cell
d) to ingest nutrients
e) as a means of cellular protection
15. What is the molecular basis of familialhypercholestremia?
a) HDL enters cells using a specific receptor on the cellsurface
b) LDL enters cells using a specific receptor on the cellsurface
c) HDL exits cells using a specific receptor on the cellsurface
d) LDL exits cells using a specific receptor on the cellsurface
e) receptor-mediated exocytosis
16. Carrier molecules are utilized for ____.
a) active transport only
b) passive transport only
c) both active and passive transport
d) osmosis
e) transport of all types of molecules
17. All of the following are functions of integral membraneproteins EXCEPT ____.
a) transport of polar molecules
b) reception of chemical signals form other cells
c) cell division
d) recognition of other cells as being "like"
e) cell-cell binding
