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

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water–equal to the volume of blood lost–is transferred directly into one of his veins. What will be the most probable result of this transfusion?

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water–equal to the volume of blood lost–is transferred directly into one of his veins. What will be the most probable result of this transfusion? 

A) It will have no unfavorable effect as long as the water is free of viruses and bacteria.
B) The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.
C) The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells.
D) The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.
E) The patient's red blood cells will burst because the blood fluid has become hypertonic compared to the cells.



Answer: C

In the small airways of the lung, a thin layer of liquid is needed between the epithelial cells and the mucus layer in order for cilia to beat and move the mucus and trapped particles out of the lung. One hypothesis is that the volume of this airway surface liquid is regulated osmotically by transport of sodium and chloride ions across the epithelial cell membrane. How would the lack of a functional chloride channel in cystic fibrosis patients affect sodium ion transport and the volume of the airway surface liquid?

In the small airways of the lung, a thin layer of liquid is needed between the epithelial cells and the mucus layer in order for cilia to beat and move the mucus and trapped particles out of the lung. One hypothesis is that the volume of this airway surface liquid is regulated osmotically by transport of sodium and chloride ions across the epithelial cell membrane. How would the lack of a functional chloride channel in cystic fibrosis patients affect sodium ion transport and the volume of the airway surface liquid? 

A) Sodium ion transport will increase; higher osmotic potential will increase airway surface liquid volume.
B) Sodium ion transport will increase; higher osmotic potential will decrease airway surface liquid volume.
C) Sodium ion transport will decrease; lower osmotic potential will decrease airway surface liquid volume.
D) Sodium ion transport will decrease; lower osmotic potential will increase the airway surface liquid volume.
E) Sodium ion transport will be unaffected; lack of chloride transport still reduces osmotic potential and decreases the airway surface liquid volume.





Answer: C

If the sodium ion concentration outside the cell increases, and the CFTR channel is open, in what direction will chloride ions and water move across the cell membrane?

If the sodium ion concentration outside the cell increases, and the CFTR channel is open, in what direction will chloride ions and water move across the cell membrane? 

A) Chloride ions will move out of the cell, and water will move into the cell.
B) Both chloride ions and water will move out of the cell.
C) Chloride ions will move into the cell, and water will move out of the cell.
D) Both chloride ions and water will move into the cell.
E) The movement of chloride ions and water molecules will not be affected by changes in sodium ion concentration outside the cell.





Answer: B

Cystic fibrosis is a genetic disease in humans in which the CFTR protein, which functions as a chloride ion channel, is missing or nonfunctional in cell membranes. The CFTR protein belongs to what category of membrane proteins?

Cystic fibrosis is a genetic disease in humans in which the CFTR protein, which functions as a chloride ion channel, is missing or nonfunctional in cell membranes.
The CFTR protein belongs to what category of membrane proteins? 

A) gap junctions
B) aquaporins
C) electrogenic ion pumps
D) cotransporters
E) hydrophilic channels






Answer: C

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in 

A) peroxisomes.
B) lysosomes.
C) Golgi vesicles.
D) vacuoles.
E) secretory vesicles.





Answer: B