Exam 3 Test Questions Flashcards
Of the following, the motor protein that interacts with microtubules is A. kinesin B. vimentin C. myosin D. lamin E. keratin
A. kinesin
Actin and myosin A. interact to move cilia and flagella B. are the basis for contraction in muscle cells C. are employed for motion in the amoeba D. A and B E. B and C
E. B and C
Dynein and tubulin
A. interact to move cilia and flagella
B. are the basis for contraction in muscle cells
C. are employed for motion in the Paramecium and Trypanosome
D. A and C
E. B and C
D. A and C
Which is NOT true about integral membrane proteins?
A. They are less tightly bound to the membrane than peripheral ones.
B. They move laterally in the plane of the membrane according to the fluid mosaic model
C. They generally have an intracellular domain, an extracellular domain, and a transmembrane domain
D. They include carrier and channel proteins involved in membrane transport
E. All of the above are true
A. They are less tightly bound to the membrane than peripheral ones.
A membrane is made more fluid by having phospholipids with A. unsaturated fatty acids B. saturated fatty acids C. long fatty acids D. A and C E. B and C
A. unsaturated fatty acids
The fluid mosaic model
A. states that membrane lipids are free to move around in the plane of the phospholipid bilayer
B. states that membrane proteins are free to move into and out of the phospholipid bilayer
C. states that the cytoskeleton holds pieces of the membrane lipids in fixed places, much like the pieces in a mosaic of tile or stained glass
D. A and B
E. B and C
A. states that membrane lipids are free to move around in the plane of the phospholipid bilayer
Cells that form layers surrounding the lumen of an internal cavity in metazoans (higher animals)
A. are called epithelial cells
B. are connected to neighboring cells by hemiplasmodesmatoids that prevent the leakage of material from the lumen into the rest of the body
C. are separated from the rest of the body by a basal lamina (basement membrane)
D. A and B
E. A and C
E. A and C
Suppose a monolayer of phospholipids spreads out into an area equal to the surface area of the red blood cells that the phospholipids came from. Which of the following would be true? (Hint, assume the plasma membrane has constant thickness.)
A. the plasma membrane of the red blood cells would be one molecule thick
B. the plasma membrane of the red blood cells would be two molecules thick
C. the plasma membrane of the red blood cells would be three molecules thick
D. the plasma membrane of the red blood cells would be four molecules thick
E. the plasma membrane of the red blood cells would be a bilayer
A. the plasma membrane of the red blood cells would be one molecule thick
Plasma membranes A. cover only eukaryotic cells B. contain only phospholipid C. are thin, flexible coverings D. all of the above E. none of the above
C. are thin, flexible coverings
A membrane includes a channel protein for facilitated diffusion that is always active and specific for K+ ions. This membrane will
A. Transport more K+ ions when the concentration of K+ ions increases, but only up to a point where the rate of transport doesn’t increase further
B. Transport proportionately more K+ ions when the concentration of K+ ions increases without a limit to the increase in the rate of transport
C. Show saturation kinetics for K+ transport
D. A and C
E. B and C
B. transport proportionately more K+ ions when the concentration of K+ ions increases without a limit to the increase in the rate of transport
Solution A is hypertonic compared to a cell. Which of the following is true?
A. Solution A has a lower concentration of solutes than the cell does
B. Solution A has a higher concentration of solutes than the cell does
C If the cell is put in solution A, the cell will gain water and may burst
D. A and C
E. B and C
B. solution A has a higher concentration of solutes than the cell does
If a molecule is not permeable to a lipid bilayer and present in higher concentration inside than outside the cell, what mechanism could it use to get into a cell?
A. simple diffusion
B. facilitated diffusion via a channel or carrier protein
C. active transport via a transporter protein
D. A and C
E. B and C
C. active transport via a transporter protein
Cashew trees grow in warmer environments than almond trees. As a result the triglycerides in cashews
A. have more saturated fatty acids than in almonds
B. have more unsaturated fatty acids than in almonds
C. have shorter fatty acids than in almonds
D. A and B
E. B and C
A. have more saturated fatty acids than in almonds
Facilitated diffusion
A. is movement of molecules that are permeable to the lipid bilayer down the concentration gradient
B. is movement of molecules through carriers or channels down the concentration gradient
C. is movement of molecules from low to high concentration using energy
D. always shows linear kinetics
E. is often coupled to active transport
B. is movement of molecules through carriers or channels down the concentration gradient
Simple diffusion
A. is movement of molecules through carriers or channels down the concentration gradient
B. is movement of molecules from low to high concentration using energy
C. is movement of molecules that are permeable to the lipid bilayer down the concentration gradient
D. transports glucose through the membrane
E. C and D
C. is movement of molecules that are permeable to the lipid bilayer down the concentration gradient