The units of structure that build protein and are joined together end to end like pop beads are _____.

Hair is approximately _____ percent protein.

What substances are comprised of long, coiled, complex polypeptides made of amino acids?

The three different types of side bonds that link chains of amino acids together are _____.

A physical side bond that is easily broken by water and heat is a _____ bond.

What type of bond is broken by wetting the hair with water and is reformed when the hair dries

A weak, physical, cross-link side bond between adjacent polypeptide chains that is broken by changes in pH is a _____ bond.

Permanent waving and hair relaxers change the shape of hair by chemically altering the hair’s _____.

Hydroxide chemical relaxers break disulfide bonds and convert them to _____ bonds.

All natural hair color is the result of pigment called _____.

The pigment that provides brown or black color to hair is _____.

What pigment in hair provides natural colors ranging from red and ginger to yellow and blond tones?

What term refers to the shape of the hair strand?

What is the cross-section shape of curly hair?

Vellus hair is also known as _____ hair.