Chapter 20 Flashcards
what gives 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?
chemical texture services
without a thorough understanding of what, cosmetologists could damage hair, cause hair loss, and harm their clients and themselves?
chemistry
what tough exterior layer of the hair has the purpose of surrounding the inner layers and protecting the hair from damage?
cuticle
which layer of the hair is located directly beneath the cuticle layer and is responsible for the incredible strength
and elasticity of human hair?
cortex
which layer of hair is the innermost layer of the hair, and often called the pith or core of the hair?
medulla
the what measures the acidity and alkalinity of a substance by measuring the quantity of hydrogen ions it contains?
pH scale
the range of numbers used in the pH scale is what?
0 to 14
chemical hair texturizes temporarily raise the prof the hair to an alkaline state in order to what?
soften and swell the shaft
in the restructuring process, coarse, resistant hair with a strong compact cuticle requires a chemical solution that is what?
highly alkaline (more alkaline)
what are the basic building blocks of hair that affects how chemical solutions react?
amino acids, peptide bonds, polypeptide chains, keratin proteins, and side bonds.
which compounds are made up of carbon, oxygen, hydrogen, nitrogen, and sulfer?
amino acids
which chemical bonds, also known s end bonds, join amino acids together, end to end in long chains to form a polypeptide chain?
peptide bonds
what are long, coiled polypeptide chains linked together end to end like beads
keratin proteins
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?
disulfide, salt and hydrogen bonds
what chemical side bonds are formed when tow sulfer type chains are joined together
disulfide bonds
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?
salt bonds
Hydrogen bonds are weak physical side bonds that result from an attraction between negative and positive electrical charges and are easily broken by water or heat, but reform as the hair is what?
dried
what is a two step process in which the hair first undergoes a physical change caused by wrapping the hair on perm rods, and then a chemical change caused by the application of permanent waving solution and neutralizer?
permanent waving
what determines the size of the curl in a permanent waving process
the size of the rod
in permanent waving , the shape and type of curl are determined by the shape and type of rod and the what?
wrapping method
once in the cortex, the reduction reaction called what?
reduction
in permanent waving, the reduction reaction is due to the addition of what
hydrogen
what are the most common reducing agents used in permanent waving?
thioglycolic acid
the what of the permanent waving solution is determined primarily by the concentration of the reducing agent or thio
strength
