Question

A student observes a liquid substance in water which beads up on the surface of water and does not dissolve. This substance must be:

A.) A protein
B.) A carbohydrate
C.) A lipid
D.) A nucleic acid

Answer 1

A lipid

Step-by-step explanation:

Have you ever tried to mix oil with water? You'll notice it forms droplets or a layer on top, but will not mix with the water.

Lipids form an emulsion in water and will not dissolve. This is because they are insoluble in water.

Lipids are insoluble in water because they form long non-polar chains which are hydrophobic, meaning they repel water and will not mix with it.