Unit 2 - Fragrences & Skincare Flashcards
What are essential oils?
Extracts of volatile, non-water soluble aroma compounds from plants
Where are essential oils extracted from?
The essence of the plant
Where are essential oils commonly used?
Perfumes, cosmetic products and food flavourings
How can essential oils be extracted?
Steam distillation
How many Carbons are in a terpene?
C5H8
What’s the name for an isoprene?
2-methylbuta-1,3-diene
How many terpene units are in a compound containing 20 carbons?
4
Define a free radical
An atom or molecule with an unpaired electron
What is required to form free radicals?
UV light
What are the 3 steps in free radical reactions?
- Initiation
- Propagation
- Termination
What is a free radical scavenger?
Molecules that can react with free radicals to form stable molecules thus preventing chain reactions from occurring.
Name 3 things that contain free radical scavengers.
- Cosmetic and anti-aging products.
- Foods
- Plastics (prevents them from breaking down under UV light)
Describe the impact of UV light on skin.
UV light from the sun has enough energy to break chemical bonds and can cause chemical reactions to occur in our skin, producing free radicals. Ultraviolet (UV) light causes sunburn, skin cancers and can accelerate the aging process of skin. The UV radiation destroys the collagen, one of the proteins which helps give skin a firmness.
What are the best suncreams?
Ones that protect from UVA and UVB.
What does UVA do to skin?
Accelerating the aging process by damaging collagen, resulting in wrinkles. Think ‘UVAging’.
What does UVB do to the skin?
Sunburns and damaging the DNA in skin cells. Think ‘UVBurning.’
How does sunblock work?
They usually contain zinc oxide and titanium dioxide, which block the UV rays and do not allow them to pass through the skin.
How do sunscreens work?
They contain substances which absorb some of the UV rays reducing the amount that reaches the skin.
What type of sun cream is more effective?
Sunblock
Can free radical chain reactions occur in the dark?
No - they need UV light to break the covalent bonds. Once started, they can continue in the dark.
What is a free radical chain reaction?
Alkanes are saturated they will not take part in addition reactions with halogens. However alkanes can react with halogens to produce haloalkanes in a different type of reaction called a free radical chain reaction.
What happens in the initiation step?
Involves UV light from the sun Breaking the covalent bond in the Halogen and so creating two free radicals.
(one reaction involved)
What happens in the propagation step?
One free radical reacts with a stable molecule to create another free radical. (two reactions involved)
What happens in the termination step?
Two free radicals combine to create a stable molecule. (three reactions involved)
