Question 755
{"accessible":false,"alternatives":[{"id":3829,"text":"being directly hit by a photon"},{"id":3830,"text":"by reaction with free radicals"},{"id":3831,"text":"by reaction with other toxic substances resulting from irradiation"},{"id":3832,"text":"all of the above"},{"id":3833,"text":"none of the above"}],"archived":false,"correctAlternativeId":3832,"explanation":"\u003cp\u003eRadiation damage to organic molecules occurs almost exclusively by free-radical interactions. Ionizing radiation exposure can produce free radicals in abundance through excitation processes. In cells, water is the most abundant source of radiation-produced hydrogen and hydroxyl free radicals. These can interact with molecules involved in cellular metabolism, for instance, and the normal function of the cell may become impaired. They can also interact with nucleic acid molecules which can result in cellular mutations or even cell death.\u0026nbsp;Chain reactions can also occur where a free radical binds with a neighboring molecule and as a result generates another free radical.\u003c/p\u003e\u003cp\u003eAdapted from\u0026nbsp;\u003ca href=\"https://en.wikibooks.org/wiki/Basic_Physics_of_Digital_Radiography\"\u003eBasic Physics of Digital Radiography\u003c/a\u003e\u0026nbsp;by\u0026nbsp;Kieran Maher,\u0026nbsp;with author's permission (License:\u0026nbsp;\u003ca href=\"https://creativecommons.org/licenses/by-sa/3.0/\"\u003eCreative Commons\u0026nbsp;BY-SA 3.0\u003c/a\u003e).\u003c/p\u003e","id":755,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/782","nextQuestionPath":"/articles/biomolecular-radiation-damage/questions/705","relatedArticles":[],"alsoUsedIn":[],"stem":"\u003cp\u003eThe DNA molecule may be damaged by...\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/755"}],"attemptsPercentages":[{"alternativeId":"3830","percentage":16},{"alternativeId":"3833","percentage":1},{"alternativeId":"3832","percentage":73},{"alternativeId":"3829","percentage":7},{"alternativeId":"3831","percentage":3}],"promptToLogin":false,"questionManager":false,"articleId":"biomolecular-radiation-damage"}