#Question id: 2219
#Unit 2. Cellular Organization
Cholesterol and phospholipids are transported between organelles by
i. Golgi-dependent mechanisms.
ii. incompletely characterized vesicle populations.
iii. direct contact between membranes and, to some extent, small, soluble lipid-transfer proteins.
Which of the following statements are correct?
#Question id: 2220
#Unit 2. Cellular Organization
Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?
#Question id: 2221
#Unit 2. Cellular Organization
The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
At the beginning of the U-tube experiment illustrated above, which of the following statements is true?
#Question id: 2222
#Unit 2. Cellular Organization
The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium?
#Question id: 2223
#Unit 2. Cellular Organization
Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed), and the percent change in mass of each bag was graphed.
Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment?
#Question id: 2224
#Unit 2. Cellular Organization
Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed), and the percent change in mass of each bag was graphed.
Which line in the graph represents the bag with the highest initial concentration of sucrose?