Melanin Physiology: Melanin Absoprtion of UV Light and Internal Conversion to Heat

The video explains the importance of melanin in protecting skin DNA from UV light. It covers the mechanism of DNA mutation through thymine dimers and how melanin acts as a protective barrier. The structure of melanin, including its monomers, is discussed, along with its mechanism of action, which involves absorbing UV light and dissipating energy as heat to prevent DNA damage.

What is the primary function of melanin in the skin?

• To regulate body temperature

• To provide color to the skin

• To moisturize the skin

• To protect DNA from UV light

What can cause DNA mutations when exposed to UV light?

• Production of vitamin D

• Formation of cyclobutane thymine dimers

• Loss of skin moisture

• Increase in skin temperature

How does melanin help prevent DNA mutations?

• By producing antioxidants

• By increasing skin thickness

• By absorbing UV light

• By reflecting UV light

What are the two main monomers that make up melanin?

• Amino acids and proteins

• Dihydroxy indole and dihydroxy indole carboxylic acid

• Nucleotides and sugars

• Lipids and carbohydrates

What is the role of melanocytes in the skin?

• To produce keratin

• To produce collagen

• To produce elastin

• To produce melanin

What process allows melanin to dissipate absorbed UV energy as heat?

• Internal conversion

• Radiation emission

• Photosynthesis

• Fluorescence

What percentage of UV light is absorbed by melanin?

• 100%

• 99.9%

• 50%

• 75%

What happens to electrons in melanin when they absorb UV light?

• They decrease in energy

• They go into an excited state

• They are emitted as light

• They remain unchanged

What is the consequence of DNA absorbing UV light?

• It becomes less reactive

• It becomes more stable

• It undergoes mutations

• It produces more melanin

What is the main danger of free radicals in DNA?

• They cause dehydration

• They enhance vitamin D production

• They lead to mutations and cancer

• They increase skin elasticity