Dna - Alpha, Beta, and Gamma Radiation

DNA

Scientists have a window back into history to figure out what different types health issues people have carried from one generation to next. Human DNA is a system that supports the human body to work properly to stay in good heath and fight diseases. "Nucleic acids contain a chemical code that specifies the correct amino acid sequences for proteins" (Tro, 2009). Nucleic acids include deoxyribonucleic acid or DNA, which exists primarily in the nucleus of the cell, and ribonucleic acid or RNA, which is found throughout the entire interior of the cell.

In some cases DNA changes and forms cancerous cells; different radiation methods are used to treat these types of changes. These types of radiation will affect the DNA sequence; the three types of radiation, aplha, beta, and gamma affect the body differently. The section ionize radiation describes how changes in the DNA become cancerous.

Alpha, Beta, and Gamma Radiation

Alpha (α) radiation is the weakest of the three radiations discussed. An alpha particle consisting of two neutrons and two protons is released from an unstable atom, the product idenitical to that of a helium atom's nucleus. The parent nuclide becomes lighter as shown by the decreased mass number, minus four, and decreased atomic number, minus two (Bishop, 2009). The alpha particles are the largest of the three radiations. Their size increases the particles' likelihood to interact with other atoms, but they have limited penetration capabilities (Tro, 2009). Alpha particles can greatly damage the atoms with which they interact but have minimal danger of damaging human cells. Just as the particles cannot penetrate paper, they cannot penetrate human skin. It is important not to allow alpha particles to enter the body through inhalation, ingestion, or injection because they can do serious damage to atoms once within the perimeter of the body.

Beta (β) radiation involves release of an electron. In this case there is instability between the neutrons and protons. One neutron splits into a proton and electron. The atom releases the electron, resulting in a new element that has an identical mass number and an increased atomic number, plus one (Bishop, 2009). Beta particles are larger than alpha particles. The size increase permits more powerful penetration but less effect on surrounding atoms with which it interacts (Tro, 2009). Beta particles can penetrate human skin but will do less damage to the body than alpha particles once inside the body.

Gamma (γ) radiation is different from the previous two forms because it does not change either the mass number or atomic number. Gamma radiation involves electromagnetic radiation, unlike the matter involved in alpha and beta radiation (Tro, 2009). Bishop likens gamma rays to "streams of high energy photons" (2009). Gamma rays have the highest penetrating power of the three types of radiation; it can more easily enter the body than beta particles. Whereas a few centimeters of aluminum can stop beta rays, it takes "several inches of lead shielding or thick slabs of concrete" to halt gamma radiation (Tro, 2009). Thus, although gamma rays can easily access the internal body, gamma radiation has significantly less effect on atoms than alpha rays.

Describe the chemistry of DNA

DNA contains the molecular blueprints for the human body. Each cell, protein, and gene functions by these instructions. The DNA is in the nucleus of each cell structured as a double-stranded helix (Tro, 2009). Each strand is held together at the base by hydrogen bonds, specific to other certain strands. The DNA strands consist of polymers and monomers called nucleotides. These nucleotides include Cytosine (C), Thymine (T), Guanine (G), and Adenine (A). Simon, Reece, & Dickey, (2009), state, "Nucleotides are joined together by covalent bonds between the sugar of one nucleotide and the phosphate of the next in a repeating pattern" (p. 174). The bonding process helps in replication as there is a certain pattern; Adenine and Thymine bond together, and Cytosine and Guanine bond together. This enables polynucleotide strands to have the same genetic code within the same system or body. Recently, it has been found that scientists can change and manipulate DNA. This can help them find a way to change the harmful effects that radiation and cancer have on the reproduction of new strands of DNA in human cells. If a strand is healthy and something interferes, the DNA strand will continue to make copies of the harmful codes.

Explain the effects of radiation

In a living cell radiation causes ionizations in the cells molecules. According to Radiation And Risk (2005), "These ionizations result in the removal of electrons from the atoms, forming ions or charged atoms. The ions formed then can go on to react with other atoms in the cell, causing damage." (para. 3). Low doses of background radiation that people receive daily are easily repairable for cell. Higher doses such as 1 Sv, cells have difficulty repairing