Fragrances/ Skin Care Flashcards
What are essential oils? (3 statements)
- Organic products which are concentrated extracts from plants
- They are volatile and non-water soluble
- Used in perfumes, cosmetic and cleaning products and flavourings
What are terpenes?
Unsaturated compounds formed by joining together isoprene units
What is the common name for an isoprene?
2-methylbuta-1,3-diene
How many carbons does one isoprene contain?
5
How do you calculate the number of isoprene molecules in a structure?
Count the number of carbons and divide by 5
What are terpenoids?
Terpenes containing oxygen or other functional groups
What happens when terpenes are oxidised?
They produce compounds that are responsible for the aroma of spices
What is Ultraviolet (UV) light?
(3 statements)
- A high-energy form of light, present in sunlight
- Can provide sufficient energy to break bonds within molecules. This causes sunburn and aging of the skin
- Sun-block products prevent UV light reaching the skin
What are free radicals?
Atoms or molecules that are highly reactive due to the presence of unpaired electrons
How are free radicals formed?
When UV light break bonds
Why do free radicals react quickly with other compounds?
Because they are unstable and react quickly to capture the needed electron to gain stability
What do free radical scavengers do?
They react with free radicals to from stable molecules and prevent chain reactions
What are free radicals scavengers added to?
Cosmetic products, food and plastics
What are the 3 stages in a chain reaction?
Initiation, propagation and termination
What is the initiation step in the chain reaction of
Cl2 + H2 –> 2HCl
The UV light breaks down some of the Cl-Cl bonds to form chlorine radicals:
Cl2(g) –> Cl(g) + Cl*(g)
What is the propagation step in the chain reaction of
Cl2 + H2 –> 2HCl
Chlorine free radicals react with H2 molecules
H2(g) + Cl* –> H*(g) + HCl(g)
The product id called a hydrogen radical which react with chlorine molecules
What is the termination step in the chain reaction of
Cl2 + H2 –> 2HCl
What class of terpenes do molecules with 2 isoprene units belong to?
Monoterpene
What class of terpenes do molecules with 3 isoprene units belong to?
Sesquiterpenes
What class of terpenes do molecules with 4 isoprene units belong to?
Diterpenes
