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There are two main ways radiation can damage DNA inside living cells. Radiation can strike the DNA molecule directly, ionizing and damaging it. Alternately, radiation can ionize water molecules, producing free radicals that react with and damage DNA molecules.
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How can radiation damage a living cell?

High frequency radiation or fast moving particles plow into a living cell with enough energy to knock electrons free from molecules that make up the cell. These molecules with missing electrons are called ions. The presence of these ions disrupts the normal functioning of the cell.

The most severe damage to the cell results when the DNA (deoxyribonucleic acid) is injured. DNA is at the heart of the cell and contains all the instructions for producing new cells. The DNA is a complex molecule formed of two long strands that are twisted around each other and linked by chemical subunits.

There are two major ways that radiation injures the DNA inside your cells. 1) The water in your body tends to absorb a large portion of the radiation and becomes ionized. When water is ionized it readily forms highly reactive molecules called free radicals. These free radicals can react with and damage the DNA molecule. 2) Alternatively radiation can collide with the DNA molecule, itself, ionizing and damaging it directly.

Symptoms of radiation sickness: severe burns that are slow to heal, sterilization, cancer, and other damage to organs. High doses are rapidly (within days or weeks) fatal.

Mutations or changes in the DNA can be passed along to offsprings. Mutations are generally for the worse.

Depending upon the type and severity of the damage caused to the DNA by the radiation, the cell might (or might not!) be able to repair itself.

Last modified June 24, 2008 by Randy Russell.

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Traveling Nitrogen is a fun group game appropriate for the classroom. Players follow nitrogen atoms through living and nonliving parts of the nitrogen cycle. For grades 5-9.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA