JENNIFER HODGES

• Direct-Occurs when ionizing radiation interacts directly with vital macromolecules (DNA,RNA) IN VIVO
• Indirect-Occurs when a photon strikes noncritical molecules (WATER) and transfers the energy to target molecules (BOTH CAN HIT THE TARGET CELL)

It's target molecule must be inactivated (DNA DOESN'T HAVE TO BE DESTROYED)

DNA is always the target. Radiation damage to non-abundant molecules necessary for normal cell function could affect the cell severely b/c no similar molecule would be available to replace it.

• Directs-Ionization of DNA
• Indirect-Ionization of water a non-critical molecule

They are uncharged molecules that contains a single unpaired electron in the outer shell. the are HIGHLY REACTIVE and UNSTABLE. They contain excess energy that can be transferred to other molecules to disrupt bonds and produce point lesions-Radiation hits the cell and knocks out electrons.

HAPPENS ONLY AFTER MAIN CHAIN AND IT CONNECTS IN MANY DIFFERENT WAYS. They are macromolecules that have small spur likestructures on sides that attach to similar macromolecules which INCREASES the viscosity of a macromolecule solution.

A breakage in long chain molecules resulting in smaller molecules. It reduces the size and viscosity of the solutions. (ONLY ONE WHERE THE CHAIN BREAKS) (MACROMOLECULES AREN'T DESTROYED BUT TRANSFERRED INTO NEW MOLECULES)

OCCURS WHEN CHEMICAL BONDS OF MOLECULES ARE DISRUPTED, BUT DNA STRAND IS NOT BROKEN BUT COULD BE CHANGED. MUTATION MORE CRITICAL.

• May lead to LATE EFFECTS(DIRECT DAMAGES)
• Loss of cell function
• Affects daughter cells
• can prevent cells from reproducing
• DEATH, CHANGES METABOLIC ACTIVITY, MALIGNANT DISEASE

When water is irradiated it dissociates into other molecular products. Radiation hits hydrogen electrons and kicks it out.

DNA

Water-Radiation interacts with water b/c our body is made up of 80% water.

Linear Energy Transfer-The higher the LET the increase chance a master molecule will be directly affected, (BECOMING INACTIVATED)

• OH*-Hydrogen Peroxide H2O2
• H*-Hydroperoxyl Radicals

• HOH+e-
• Hydrogen peroxide-H2O2
• Hydroperoxyl Radical-H*+O2=HO2

Loses e- 2ion pairs produced (atom with +or- charge)

• THEY CAN ATTACH TO OTHER MOLECULES
• THEMSELVES
• OR JOIN TO OTHER BROKEN MOLEUCLES

Outside the body or cell

Within the living cell

• Predicts cell radiosensitivity
• Different cells respond to radiation differently
• Radiosensitivity is directly proportional to a cell's reproductive activity and inversely proportional to its degree of differentiation.
• Cell's that are most sensitive to radiation are those that reproduce most quickly and immature and have least degree of specialization.
• Cells that are most resistant to radiation are those that reproduce slowly and have high degrees of specialization.

Point lesion-Changes molecules and causes malfunction with in cell.

Long chain molecules break, NOT DESTROYED BUT TRANSFERRED INTO MOLECULES. Decreases viscosity of fluid in cell.

• Hydrogen Peroxide
• Hydroperoxyl Radical