Plant parts with Allergenic Activity from the chemical OLEIC-ACID
Molecules that are repelled by water are called hydrophobic. Molecules that are attracted to water are called hydrophilic. Cooking oil is hydrophobic; it won't mix with water. Some molecules have one end that is hydrophobic and one end that is hydrophilic. There are such molecules in the cells in your body. They are used to take hydrophobic nutrients into the cell that is mostly water. Soaps are this way also so that they can dissolve both hydrophobic and hydrophilic substances and be washed away by water.
Oleic acid is a substance with one hydrophobic and one hydrophilic end. When a small amount of oleic acid is placed on the surface of water, it stands on end with the hydrophilic end towards the water and the hydrophobic end away. If you could see them, they would look like fans at a crowded concert.
In this lab, we will find the length of one oleic acid molecule by spreading a small amount over the surface of water and measuring the diameter of the circle. The oleic acid spreads itself into a one-molecule thick layer in the shape of a VERY flat cylinder.