The cortex of the hair is made up of millions of polypeptide chains cross-linked by three types of side bonds that are responsible for the elasticity and strength of the hair. These bonds are ___.

What tough exterior layer of the hair has the purpose of surrounding the inner layers and protecting the hair from damage?

___ give you the ability to permanently change the hair's natural wave and curl pattern, thereby offering clients a variety of styling options that would not otherwise be possible.

Which bonds are relatively weak physical side bonds resulting from an attraction between negative and positive electrical charges, and are easily broken by changes in pH?

Which layer of the hair is located directly beneath the cuticle layer and is responsible for the incredible strength and elasticity of human hair?

Which compounds are made up of carbon, oxygen, hydrogen, nitrogen, and sulfur?

What are long, coiled polypeptide chains linked together end-to-end like beads?

The ___ measures the acidity and alkalinity of a substance by measuring the quantity of hydrogen ions it contains.

In the restructuring process, coarse, resistant hair with a strong compact cuticle requires a chemical solution that is ___.

Which chemical bonds, also known as end bonds, join amino acids together, end-to-end in long chains, to form a polypeptide chain?