In Vivo Irradiation Effects on Macromolecules

Play an AI-generated podcast conversation about this lesson

What is the primary target of radiation in the biological system?

Cell membrane

Ribosomes

DNA molecule (correct)

Mitochondria

What is the primary mechanism by which radiation causes biological effects?

Both direct and indirect effects (correct)

Neither direct nor indirect effects

Direct effect

Indirect effect

What is the role of free radicals in the biological effects of radiation?

Free radicals have no effect on biological systems

Free radicals are energetic molecules that can transfer their excess energy to DNA, causing bond breaks (correct)

Free radicals are stable molecules that do not interact with DNA

Free radicals act as antioxidants to protect against radiation damage

How is hydrogen peroxide formed during the radiolysis of water?

Hydrogen peroxide is formed by the interaction of two hydroxyl radicals Signup and view all the answers

What is the role of hydroperoxyl radicals in the radiolysis of water?

Hydroperoxyl radicals are formed by the interaction of hydrogen radicals with oxygen Signup and view all the answers

Which of the following is a biologic factor that affects radiosensitivity?

All of the above Signup and view all the answers

Which of the following statements is correct about the effect of radiation on chromosomes?

Radiation-induced chromosome aberrations follow a non-threshold dose-response relationship. Signup and view all the answers

What are isochromatids in the context of radiation-induced chromosome aberrations?

A type of chromosome aberration where a chromosome has extra material. Signup and view all the answers

Which of the following statements is correct about the effect of radiation on DNA?

Radiation can interact with DNA through direct and indirect effects. Signup and view all the answers

What does a 'single-hit' refer to in the context of radiation-induced chromosome aberrations?

A chromosome that has been hit by a single radiation particle. Signup and view all the answers

Which of the following statements is incorrect about the effect of radiation on skin cells?

The dose-response relationship for radiation-induced skin damage is linear and non-threshold. Signup and view all the answers

Which of the following cells are described as the most radiosensitive in the body?

Lymphocytes and spermatogonia Signup and view all the answers

What is the primary target of radiation in a cell?

DNA Signup and view all the answers

Which type of DNA damage is considered lethal for a cell?

Double-strand breaks Signup and view all the answers

What is the primary mechanism by which cells die after irradiation?

Mitotic death Signup and view all the answers

What is the consequence of a base damage in DNA?

It alters the base sequence, potentially causing a mutation Signup and view all the answers

Which of the following is a direct effect of radiation on water molecules?

All of the above Signup and view all the answers

What is the primary mechanism by which radiation causes damage to DNA?

Both direct ionization and indirect damage through free radicals Signup and view all the answers

What is the primary consequence of a double-strand break in DNA?

It may lead to cell death Signup and view all the answers

Which of the following is NOT a type of radiation damage described in the text?

Irreversible damage Signup and view all the answers

What is the primary function of DNA in a cell?

Storing genetic information Signup and view all the answers

Which of the following statements about single-strand breaks in DNA is correct?

They are relatively inconsequential and can be efficiently repaired Signup and view all the answers