2.9 skin care Flashcards
What can UV light do to molecules
provide sufficient energy to break bonds within molecules
What is UV radiation?
a high-energy form of light present in sunlight that can break chemical bonds
What are the effects of UV radiation on the skin?
- causes sunburn
- accelerates ageing of the skin
How does sunblock protect you?
prevents the UV light from reaching the skin
What happens when UV light breaks bonds?
free radicals are formed
What are free radicals?
atoms or molecules that are highly reactive due to the presence of unpaired electrons
What are the 3 steps in free radical chain reactions?
- initiation
- propagation
- termination
What are free radical scavengers?
molecules that react with free radicals to form stable molecules and prevent free radical chain reactions from occurring.
Name 3 products that free radical scavengers are added to?
- cosmetics
- food products
- plastics
What is the high-energy form of radiation present in sunlight?
UV
How can you prevent damage caused by UV radiation?
sunblock
What happens in the initiation stage of a free radical reaction?
UV light break bonds in a molecules, producing free radicals
What happens in the propagation stage of a free radical reaction?
free radicals react with other molecules, producing other free radicals but the number of free radicals on either side of the equation remains the same
What happens during the termination stage of a reaction?
two free radicals combine to form stable molecules
