Hydrophilic – Molecules or substances that are attracted to water.

Hydrophilic – Molecules or substances that are attracted to water.

Polar – Molecules having static electric charges, which can interact with water.

Nonpolar – Molecules that do not have static electric charges, and are much more likely to interact with other nonpolar molecular than with water.

Lipophilic – Substances that are attracted to fat, different than hydrophobic.

Quiz

1. Some amino acids are hydrophobic, and some are hydrophilic. Hydrophobic amino acids tend to cluster together in large proteins. Why is the order of amino acids in a protein important?

A. The order determines the shape of the protein

B. It is not important, as long as all of the amino acids are present

C. Proteins are recognized by sequence of amino acids

Answer to Question #1

2. A substance is created that has very strong electrical dipoles on the molecules, but does not interact with water, due to the strong interaction it has with itself. How would you describe the molecule?

A. Hydrophilic and polar

B. Hydrophobic and nonpolar

C. Hydrophobic and polar

Answer to Question #2

3. Many reptiles, even desert-dwelling reptiles, have hydrophobic scales on the outside of their body. Why would a desert reptile want a hydrophobic covering?

A. To repel harmful sun-rays

B. The barrier also works to stop evaporation

C. To be protected from acid rain

Answer to Question #3