Damage types from radiation

Question 1

What are the two damage types from radiation (types of radiation interactions)

Answer 1

Direct damage, and indirect damage

Question 2

How does direct damage occur

Answer 2

When ionizing radiation hits the target cells (DNA, RNA etc) and breaks the bonds between nucleic acids.

Question 3

How does indirect damage occur

Answer 3

When ionising radiation hits water (or another molecule in the cell) , ions and free radicals are produced which bond with a DNA molecule changing its structure. This is like secondary damage, because it did not hit the DNA itself first.

Question 4

Which type is more likely to cause more radiation damage to DNA

Answer 4

Indirect, 90% of the radiation is through indirect and 10% is through direct, The human body is 80% water, thus radiation is much more likely to hit a water molecule than the target cell.