Question

a) Describe to the difference between direct and indirect effect in the cell when radiation is incident.

b) What is their prevalence?

Answer 1

In Direct effect radiation interacts with the atoms of the DNA molecule, or some other cellular component critical to the survival of the cell.Such an interaction may affect the ability of
the cell to reproduce and, thus, survive.

In indirect effect radiation interacts with water it breaks the bond producing OH and hydrogen which may combine to form hydrogen peroxide which may damage the cell.

2.Direct radiation is not very probable for radiation with low linear energy transfer.Direct effects are typical for cells with low water content.

The absorption of radiation in biological environment depends on high water content. Up to 50% of the ionizing radiation energy can be absorbed in free water.

If a cell is exposed to radiation, the probability of the radiation interacting with the DNA molecule is very small since these critical components make up such a small part of the cell.as each cell is mostly water. Therefore, there is a much higher probability of radiation interacting with the water

Thus indirect effect is more prevalent than direct effect.