Molecular Motion Quiz: Which of the Following Best Describes?

Which of the following best describes the random movement of molecules in a solution?

What causes the dispersal of a dye when it dissolves in water?

What factors affect the rate of dispersal of a dye in a solution?

How can we observe the movement of molecules in biological systems?

What is the ultimate goal of the net movement of molecules in a solution?

Which of the following factors does NOT affect the rate of diffusion?

What is the primary determinant of a substance's direction of diffusion?

What is the main function of cellular membranes?

What term describes the passive, directional movement of molecules?

What determines the rate of diffusion, in addition to the concentration gradient?

Diffusion

Random movement of molecules in a solution is described as Brownian motion.
Dispersal of a dye in water is caused by the random movement of molecules, resulting in uniform distribution.
Factors that affect the rate of dispersal of a dye in a solution include:
Concentration gradient
Temperature
Surface area
Shape and size of molecules
Movement of molecules in biological systems can be observed through:
Microscopy
Dye dispersion
Observation of cellular processes
The ultimate goal of the net movement of molecules in a solution is to achieve equilibrium, where the concentration of molecules is uniform throughout the solution.

Factors Affecting Diffusion

The rate of diffusion is NOT affected by the color of the dye.
The primary determinant of a substance's direction of diffusion is the concentration gradient.
In addition to the concentration gradient, the rate of diffusion is also determined by the:
Temperature
Surface area
Shape and size of molecules

Cellular Membranes

The main function of cellular membranes is to regulate the movement of molecules in and out of cells.
The passive, directional movement of molecules is described as diffusion.

Test your knowledge on molecular motion and diffusion with this quiz! Learn about how molecules move and distribute in solutions, and understand why a dissolved molecule tends to move from areas of high concentration to low concentration.