Which ingredient causes oxidation and breakage of DNA?

Oxidized bases in DNA Two of the most frequently oxidized bases found by Dizdaroglu after ionizing radiation (causing oxidative stress) were the two oxidation products of guanine shown in the figure. One of these products was 8-OH-Gua (8-hydroxyguanine).

Why is guanine easily oxidized?

Guanine has the lowest redox potential of the four DNA bases [2] and is therefore the most easily oxidized.

What causes oxidation of DNA?

Mechanisms of oxidative damage to DNA bases. Of the reactive oxygen species, the highly reactive hydroxyl radical (•OH) reacts with DNA by addition to double bonds of DNA bases and by abstraction of an H atom from the methyl group of thymine and each of the C-H bonds of 2′-deoxyribose (2).

What increases oxidative stress?

Factors that may increase a person’s risk of long-term oxidative stress include: obesity. diets high in fat, sugar, and processed foods. exposure to radiation.

How is 8 Oxoguanine formed?

8-oxoguanine (8-oxoG) is formed by the oxidation of a guanine base in DNA (Fig. 10.4). It is considered to be one of the major endogenous mutagens contributing broadly to spontaneous cell transformation. Its frequent miss-pairing with adenine during replication increases the number of G–C → T–A transversion mutations.

How does oxidation affect DNA?

Oxidative DNA damage provides direct routes to mutations. While guanine usually pairs with cytosine, 8-oxo-7,8-dihydroguanine (8-oxoG), the most frequent type of oxidative base damage, may cause mispairing with adenine through a conformational change. This is one route to oxidative DNA damage induced mutations.

What is guanine made up of?

guanine, an organic compound belonging to the purine group, a class of compounds with a characteristic two-ringed structure, composed of carbon and nitrogen atoms, and occurring free or combined in such diverse natural sources as guano (the accumulated excrement and dead bodies of birds, bats, and seals), sugar beets.

Why free radicals are formed?

When cells use oxygen to generate energy, free radicals are created as a consequence of ATP (adenosine triphosphate) production by the mitochondria. These by-products are generally reactive oxygen species (ROS) as well as reactive nitrogen species (RNS) that result from the cellular redox process.

What causes free radicals?

Free radicals are highly reactive and unstable molecules that are produced in the body naturally as a byproduct of metabolism (oxidation), or by exposure to toxins in the environment such as tobacco smoke and ultraviolet light.

What mutation will 8-Oxoguanine lead to?

8-Oxoguanine, a major oxidized base lesion formed by reactive oxygen species, causes G to T transversion mutations or leads to cell death in mammals if it accumulates in DNA.

What is an Apurinic site?

In biochemistry and molecular genetics, an AP site (apurinic/apyrimidinic site), also known as an abasic site, is a location in DNA (also in RNA but much less likely) that has neither a purine nor a pyrimidine base, either spontaneously or due to DNA damage.