You isolate a compound that is insoluble in water, has alternating single and double bonds and has a bright orange color. You correctly conclude that this compound is a:

A) protein
B) nucleic acid
C) polysaccharide
D) steroid
E) carotenoid

Carotenoid

Pigments found in plants and some microorganisms, responsible for vibrant yellow, red, and orange colors and playing a role in photosynthesis.

Insoluble

A characteristic of substances that cannot dissolve in a specified solvent, such as water.

Double Bonds

Chemical bonds between two atoms involving four bonding electrons instead of the usual two, making compounds more reactive.