Chapter 4 Quizzes
If a cell is placed in an isotonic medium, there will be no net movement of water. A) True B) False
A) True
Exocytosis is a process by which cells A) release substances from the cell through pores in the cell membrane. B) release substances from the cell via vesicles. C) release substances from the cell via carrier proteins. D) bring in substances from the outside via vesicles. E) bring in substances from the outside via pores in the cell membrane.
A) release substances from the cell through pores in the cell membrane.
The sodium-potassium pump functions to pump A) sodium ions out of the cell and potassium ions into the cell. B) sodium ions into the cell and potassium ions out of the cell. C) sodium and potassium ions into the cell. D) sodium and potassium ions out of the cell. E) sodium and potassium ions in both directions across the cell membrane.
A) sodium ions out of the cell and potassium ions into the cell.
Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell. A) True B) False
B) False
Simple diffusion is defined as the movement of A) molecules from areas of higher concentration to areas of lower concentration. B) molecules from areas of lower concentration to areas of higher concentration. C) water molecules across a membrane. D) gas molecules across a membrane. E) gas or water molecules across a membrane.
A) molecules from areas of higher concentration to areas of lower concentration.
A 5% urea solution is hypotonic to a 10% urea solution. A) True B) False
A) True
Facilitated diffusion requires a specific transporter for a specific molecule. A) True B) False
A) True
If the material the cell takes in is liquid, the process is termed pinocytosis. A) True B) False
A) True
Low-density lipoprotein is brought into the cell by receptor-mediated endocytosis. A) True B) False
A) True
The binding and release of sodium or potassium ions are due to conformational changes in the protein. A) True B) False
A) True
The sodium-potassium pump is a trans-membrane protein. A) True B) False
A) True
What is the source of energy used to power the sodium-potassium pump? A) breakdown of ATP B) formation of ATP C) transport of ATP by the pump D) breakdown of GTP E) transport of GTP by the pump
A) breakdown of ATP
Facilitated diffusion is used to transport A) sugars and amino acids. B) H2O and O2. C) CO2 and O2. D) CO2 and H2O. E) sugars and H2O.
A) sugars and amino acids
Which of the following statements about receptor-mediated endocytosis is TRUE? A) it is used to transport material out of the cell B) it is not specific C) it involves clathrin-coated pits D) it involves transport of material into the cell through pores in the cell membrane E) none of the above
C) it involves clathrin-coated pits
A red blood cell placed in a hypertonic medium will A) expand. B) burst. C) shrink. D) have no change in shape. E) become a white blood cell.
C) shrink.
When sugar is mixed with water, equilibrium is reached when A) molecules of sugar stop moving. B) water and sugar molecules are moving at the same speed. C) the dissolved sugar molecules are evenly distributed throughout the solution. D) there are the same number of water molecules as dissolved sugar molecules. E) two tablespoons of coffee are added.
C) the dissolved sugar molecules are evenly distributed throughout the solution.
During one cycle, the sodium-potassium pump binds and moves. A) 1 Na+ and 2 K+. B) 2 Na+ and 2 K+. C) 2 Na+ and 3 K+. D) 3 Na+ and 2 K+. E) 3 Na+ and 3 K+.
D) 3 Na+ and 2 K+.
Facilitated diffusion occurs A) into the cell only. B) out of the cell only. C) in either direction depending on the temperature. D) in either direction depending on the concentration gradient of the molecule. E) in either direction depending on the size of the molecule.
D) in either direction depending on the concentration gradient of the molecule.
Certain white blood cells engulf microorganisms and bring them in to digest them. This process is best described as A) pinocytosis. B) osmosis. C) receptor-mediated exocytosis. D) phagocytosis. E) diffusion.
D) phagocytosis.
Diffusion is one of the processes whereby materials are exchanged between a cell and its environment. A) True B) False
True
Facilitated diffusion requires A) enzymes. B) carrier proteins. C) lipid carriers. D) carbohydrate carriers. E) lipid or carbohydrate carriers.
B) carrier proteins.
Which of the following will pass through a cell membrane most easily? A) small polar molecules B) small nonpolar molecules C) large polar molecules D) large nonpolar molecules E) large neutral molecules
B) small nonpolar molecules
Osmosis is best defined as the movement of A) molecules from an area of high concentration to an area of lower concentration. B) molecules from an area of low concentration to an area of higher concentration. C) water molecules across a membrane from an area of low water to an area of higher concentration. D) water molecules across a membrane from an area of high water concentration to an area of lower concentration. E) water molecules inside a container.
D) water molecules across a membrane from an area of high water concentration to an area of lower concentration.
The rate of diffusion is affected by which of the following? A) temperature B) size of molecules C) steepness of the concentration gradient D) A and B E) A, B and C
E) A, B and C
The molecules in a solid lump of sugar do not move. A) True B) False
FALSE