Based on the figure above, which of these experimental treatments would increase the rate of sucrose transport into the cell?

Based on the figure above, which of these experimental treatments would increase the rate of sucrose transport into the cell?

A) decreasing extracellular sucrose concentration
B) decreasing extracellular pH
C) decreasing cytoplasmic pH
D) adding an inhibitor that blocks the regeneration of ATP
E) adding a substance that makes the membrane more permeable to hydrogen ions




Answer: B

Which of the following processes includes all others?

Which of the following processes includes all others?

A) osmosis
B) diffusion of a solute across a membrane
C) facilitated diffusion
D) passive transport
E) transport of an ion down its electrochemical gradient



Answer: D

Which of the following factors would tend to increase membrane fluidity?

Which of the following factors would tend to increase membrane fluidity?

A) a greater proportion of unsaturated phospholipids
B) a greater proportion of saturated phospholipids
C) a lower temperature
D) a relatively high protein content in the membrane
E) a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses



Answer: A

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

A) spread in a continuous layer over the inner and outer surfaces of the membrane.
B) confined to the hydrophobic interior of the membrane.
C) embedded in a lipid bilayer.
D) randomly oriented in the membrane, with no fixed inside-outside polarity.
E) free to depart from the fluid membrane and dissolve in the surrounding solution



Answer: C

In what way do the membranes of a eukaryotic cell vary?

In what way do the membranes of a eukaryotic cell vary?

A) Phospholipids are found only in certain membranes.
B) Certain proteins are unique to each membrane.
C) Only certain membranes of the cell are selectively permeable.
D) Only certain membranes are constructed from amphipathic molecules.
E) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.



Answer: B

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells?

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells?

A) blood or tissue type of the patient
B) hydrophobicity of the drug molecule
C) lack of charge on the drug molecule
D) similarity of the drug molecule to other molecules transported by the target cells
E) lipid composition of the target cells' plasma membrane



Answer: D