Table of Contents
What cells are affected by UV light?
Exposure to the solar ultraviolet spectrum that penetrates the Earth’s stratosphere (UVA and UVB) causes cellular DNA damage within skin cells. This damage is elicited directly through absorption of energy (UVB), and indirectly through intermediates such as sensitizer radicals and reactive oxygen species (UVA).
Does UV damage human cells?
Ultraviolet radiation from the sun can zap DNA, damage cells, and set the stage for the subsequent development of cancer. All cells in the body rely on the same set of approximately 25,000 genes as the blueprint for the proteins they need to carry out their activities.
How does UV damage DNA?
Direct DNA damage can occur when DNA directly absorbs a UVB photon, or for numerous other reasons. UVB light causes thymine base pairs next to each other in genetic sequences to bond together into pyrimidine dimers, a disruption in the strand, which reproductive enzymes cannot copy.
How does UV light cause cells to become cancerous?
How can UV cause skin cancer? Too much UV radiation from the sun or sunbeds can damage the DNA in our skin cells. DNA tells our cells how to function. If enough DNA damage builds up over time, it can cause cells to start growing out of control, which can lead to skin cancer.
What protects the cells from UV radiation?
melanin
UVA radiation causes lesions or DNA damage to melanocytes, which are the skin cells that produce the skin pigment known as melanin. Melanin is a protective pigment in skin, blocking UV radiation from damaging DNA and potentially causing skin cancer.
How does ultraviolet light destroy bacterial cells?
Germ-Killing Light Targets the DNA & RNA of Microbes UV light produces electromagnetic energy that can destroy the ability of microorganisms to reproduce and cause inactivation of microbes by causing mutations and/or cell death.
What does UV A do?
Quick comparison chart
| UVA | UVB | |
|---|---|---|
| Short-term effects | immediate tanning, sunburn | delayed tanning, sunburn, blistering |
| Long-term effects | premature aging, wrinkles, some skin cancers | skin cancer, can contribute to premature aging |
| Source | sunlight, tanning beds | sunlight, tanning beds |
| % of the sun’s UV rays | ~95 | ~5 |
How does UV light affect RNA?
Ultraviolet (UV) irradiation can cause several types of damage to RNA: photochemical modification, crosslinking, and oxidative damage. Much of the work describing UV damage to RNA has been carried out in vitro, with a few studies suggesting damage may also occur in vivo under physiologic conditions.
How do skin cells respond to UV light?
New research shows that cells protect themselves (or not) from DNA damage caused by UV rays by means of a ‘simple switch’ mechanism inside cells, triggered by UV exposure from the sun. “When cells get DNA damage, normally they stop moving and stop responding to stimuli until they are repaired,” Macara explains.
Where would you expect UV radiation?
UV levels are higher closer to the equator. Closer to the equator the sun’s rays have a shorter distance to travel through the atmosphere and therefore less of the harmful UV radiation can be absorbed. With increasing altitude less atmosphere is available to absorb UV radiation.