Biophysics — 6-topic bundle

Radiation is simply energy moving. In biophysics, we're primarily concerned with ionizing radiation, which has enough energy to knock electrons off atoms, creating ions. This ionization is what causes damage in biological systems. Non-ionizing radiation (like radio waves or visible light) doesn't typically have enough energy to do this.

When radiation hits living tissue, it deposits energy. We measure this energy deposition as Absorbed Dose, typically in Gray (Gy). One Gray means one joule of energy absorbed per kilogram of tissue. However, not all radiation types cause the same amount of biological damage for the same absorbed dose.