The Effects of Radiation on Cells
Cancer is an ever-present threat to the health of human beings. Several types, most notably skin cancer, can be caused directly by radiation from the sun and from artificial ultraviolet lamps used in tanning beds. Radiation directly alters the DNA in the cells of our bodies.
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Radiation Features
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Literally speaking, radiation is any loss of heat by thermal energy, but cells are affected the most by ultraviolet radiation, X-rays and gamma rays. These three types of radiation have longer wavelengths than the visible spectrum of light.
Ultraviolet Radiation
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Ultraviolet radiation, which comes from the sun and artificial lamps in tanning beds, is absorbed by DNA in the nucleus of our cells. The resulting energy is used to introduce unnatural fusions between two adjacent pyrimidine bases, such as two thymines.
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Ionizing Radiation
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X-rays and gamma rays can directly ionize the backbone of DNA, which results in a double-stranded break in the DNA chain.
DNA Repair
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Dimers caused by radiation distort the shape of the DNA helix. Our cells recognize distortions as damaged DNA and attempt to repair the problem by cutting out and replacing the problem site, but this is not always successful and sometimes leads to mutations. Double-stranded breaks are extremely difficult to fix and usually result in cell death.
Cancer Treatment
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Because ionizing radiation has the potential to kill rapidly growing cells, it is often used to treat many types of cancer.
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References
- Human Anatomy and Physiology, Sixth Edition; Elaine N. Marieb; 2004
- Molecular Biology of the Gene, Fifth Edition; Watson et al.; 2004
