Download Radiation and Gene Damage

Radiation, Genes, and Mutations
Background Information
Radiation is known to be dangerous to human bodies. Millions of body cells exposed
to high-energy waves from X rays, radon gas, and ultra-violet radiation have been
permanently harmed by these emissions. The DNA of the individual cells is too delicate
to withstand the energy produced by these kinds of radiation. The DNA molecules are
torn apart or suffer drastic changes in their genetic sequencing which can lead to
mutations. Under normal conditions, DNA molecules routinely undergo some sort of
genetic alteration. During replication, or copying of the cell, mistakes in gene
sequencing often occur. However, the cell contains many repair mechanisms
that continually monitor and repair damage to DNA strands.
Radiation and Gene Damage
When cells are exposed to radiation, however, several types of molecular destruction
are possible. The DNA is both physically and chemically broken (cleaved) by the high
energy waves. Often the repair of the DNA strand by enzymes or other chemicals is not
adequate enough to put the DNA molecule back together in its proper sequence.
When replication occurs, the new strands of DNA carry the new altered sequence of
genes. As each generation of cells is produced the mutations continue to show up in the
replicated cells. These cells are often nonfunctional and become tumorous growths
such as skin cancer.
Radon
Radon gas is especially harmful to lung tissues because it enters the body through
regular breathing in a building contaminated with radon. The emissions easily damage
fragile lung tissues. Not only do the high-energy radioactive emissions destroy cellular
DNA, but other large particles tear the cell membranes apart leaving the body strained
to constantly repair the damaged tissues. Fortunately, many forms of genetic alteration
by radiation are preventable. Limiting exposure to X rays, using sunscreen, and testing
buildings for radon levels can help prevent damage to a cell’s genetic makeup.
1. What makes radiation dangerous to cells?
2. How are skin cells damaged by exposure to ultra-violet radiation?
3. In what two ways does radon destroy genetic information in lung tissue cells?
4. Why do you think it’s important that a pregnant woman always tell her health care
provider she is pregnant before receiving any X ray examination?
The DNA Code
In your cells, 3-letter DNA “words” code for specific amino acids that are used to build proteins. Proteins make your
body work.
In the code below, each 3-letter DNA “word” codes a letter of the alphabet. Use the DNA code provided here to
decipher the message below:
Enrichment