physical mutagens

• • Heat and ionising radiation
• • Radiation is any transfer of energy through space from sources→ ionising radiation has enough energy to break chemical bonds in molecules including DNA
• • The range of wavelengths known as the EM spectrum
• • The shorter wavelength and high energy of ionising radiation make it dangerous→ split off electrons causing damage to cells
• • Near-ultraviolet radiation: non-ionising and DNA damage done related to ageing
• • UVB and UVC which have shorter wavelengths are forms of ionising radiation high in energy and chemical damage they cause to DNA by breaking bonds known to be mutagenic and carcinogenic
• • Artificial UV lights use UVA→ prolonged exposure risk to health
• • Naturally occurring radiation contributing factor to skin cancer→ produces pyrimidine dimers (cross-linked nucleotides) occurring when adjacent pairs of pairs on the same strand become attached to each other preventing them from pairing with bases on complementary strands causing strands to end prematurely. Prevents normal replication and transcription. 
• • Ionising radiation: free electrons from atoms or molecules turning them into ions released can cause damage to DNA
• • Electrons pass through cells, they interact with water and particles called free radicals are released 
• • Breaks in one or both strands of DNA occur leading to deletions, particle chromosome loss, rearrangements of sequences in DNA and cross-linking of DNA with itself interfering with cell division, gene products and cell metabolism