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
Which of the following is not a form of potential energy?
A. a gradient of K+ ions across a membrane
B. unusable, disordered heat energy (“waste heat”)
C. a rock rolled up a hill
D. two positive electrical charges pushed together
E. energy stored in chemical bonds
B. unusable, disordered heat energy (“waste heat”)
The second law of thermodynamics
A. says entropy can’t be created or destroyed
B. has an associated equation, ∆S > 0, which is precisely true at any time in any isolated system (S is always increasing)
C. regulates the amount of energy
D. A and B
E. B and C
B. has an associated equation, ∆S > 0, which is precisely true at any time in any isolated system (S is always increasing)
Which of the following is not a kind of usable energy?
A. heat energy
B. light (radiant) energy
C. entropy
D. potential energy stored against any of the four fundamental forces
E. free energy
C. entropy
A cell is placed in a hypotonic solution of membrane impermeable solutes; in response
A. membrane impermeable solutes will leave the cell
B. water will LEAVE the cell both directly through the membrane and through water-specific channels (aquaporins).
C. membrane impermeable solutes will enter the cell
D. water will ENTER the cell both directly through the membrane and through water-specific channels (aquaporins).
E. water will ENTER the cell, but only through water-specific channels (aquaporins), not directly through the membrane
D. water will enter the cell both directly through the membrane and through water-specific channels (aquaporins).
Gap junctions
A. make an impermeable seal around the outside of cells
B. create a gap in the seal made by tight junctions
C. allow molecules and signals to move between animal cells
D. allow molecules and signals to move between plant cells
E. none of the above
C. allow molecules and signals to move between animal cells
In metazoans (higher animals) a layer of epithelial cells surrounds the lumen of the intestines. The contents of the intestines are kept from leaking into the rest of the body by
A. tight junctions that connect all the epithelial cells
B. a basal lamina that is secreted from the apical surface of the cells
C. a basal lamina that is secreted from the basal surface of the cells
D. an extracellular matrix that is secreted by blood cells
E. none of the above
A. tight junctions that connect all the epithelial cells
The change in free energy
A. is positive for the formation of steam from water at temperatures > 100 deg. C
B. can be calculated with the equation ∆G = ∆S - T∆H
C. is calculated as ending G minus beginning G
D. A and C
E. B and C
C. is calculated as ending G minus beginning G
The free energy concept and the second law of thermodynamics are related in that (hint, read the underlined words carefully)
A. DECREASING entropy is the requirement for a spontaneous reaction in an isolated system, while INCREASING free energy is the requirement for a spontaneous reaction in any system
B. INCREASING entropy is the requirement for a spontaneous reaction in an isolated system, and INCREASING free energy is the requirement for a spontaneous reaction in any system
C. INCREASING entropy is the requirement for a spontaneous reaction in an isolated system, while DECREASING free energy is the requirement for a spontaneous reaction in any system
D. DECREASING entropy is the requirement for a spontaneous reaction in an isolated system, and DECREASING free energy is the requirement for a spontaneous reaction in any system
E. none of the above, there is no relationship between free energy and the second law
C. INCREASING entropy is the requirement for a spontaneous reaction in an isolated system, while DECREASING free energy is the requirement for a spontaneous reaction in any system
Which of the following is(are) correct expression(s) employing the concept of free energy?
A. ∆G = ∆H - T∆S
B. ∆H = ∆G - T∆S
C. total energy = free energy - usable energy
D. A and C
E. B and C
A. ∆G = ∆H - T∆S
