Stress oxidatif Flashcards
Qu’est ce que le recepter d’electron majeur en biologie ?
O2
Qu,est ce qu’on appel des ROS (molecules) free radical
Des molécules qui contiennent un ou plus d’electrons non pairés. Cela donne une reactivité aux molecules.
Que se passe-til quand des molecules free radical partagent des electrons impairées ?
Ce fait des non radical
comment les metaux lourds forment des ROS ?
Recent studies have shown that metals, including iron, copper,
chromium, and vanadium undergo redox cycling, while cadmium, mercury, and nickel, as well as lead, deplete glutathione and
protein-bound sulfhydryl groups, resulting in the production of reactive oxygen species as superoxide ion, hydrogen peroxide,
and hydroxyl radical.
exlique Redox cycling (Cycle redox
An oxidation–reduction or redox reaction is a reaction that involves the transfer of electrons between chemical species (the atoms, ions, or molecules involved in the reaction).
Oxidation and reduction (Redox) reactions represent the transfer of electrons from an electron donor (reducing agent) to an electron acceptor (oxidizing agent
quels metaux passent par le redox cycle
iron, copper,
chromium, and vanadium
que sont les métaux redox active et redox inactive ? de quoi ça dépend ?
Que font les redox inactifs
-Redox-active metals, like iron (Fe), copper (Cu) [3], and chromium (Cr)
- redox-inactive metals like lead and cadmium
- based on their ability to participate in redox reactions.
- redox-inactive metals like lead and cadmium can cause oxidative stress by depleting of cellular antioxidants, especially thiol-containing compounds such as glutathione
que sont les cellular mechanisms involved in metal-induced oxidative stress
One crucial mechanism is the disruption of mitochondrial function [19, 20]. Metals can impair mitochondrial electron transport, leading to electron leakage and the formation of superoxide radical. This dysfunction of the mitochondria can result in an overproduction of ROS, thereby aggravating oxidative stress
Another important mechanism is the activation of NADPH oxidase, an enzyme complex that generates superoxide radicals. Metals have the ability to activate NADPH oxidase, which increases ROS production and oxidative damage. Additionally, metals can interfere with cellular signaling pathways, such as those involving nuclear transcription factors like NF-κB and AP-1, which are sensitive to redox changes
que sont les Biochemical responses to metal exposure
+ lipid peroxidation
+ meltallothionein,
+ antioxidant defense mecanism
+ heat shock Proteines
+ Nrf2 Keap1 Pathway
+ Apoptosis and carcinogenesis
+ Enzyme activity alteration
+ Lipid peroxidation
what is Lipid peroxidation
Lipid peroxidation can be described generally as a process under which oxidants such as free radicals attack lipids containing carbon-carbon double bond(s), especially polyunsaturated fatty acids
Lipid peroxidation refers to the attack of free radicals on lipids that contain carbon-carbon double bond(s), particularly in cell membranes. This process ultimately causes damage to cells and increases their permeability.
Que sont les mellationeines
Metallothioneins (MTs) are low molecular weight proteins that are rich in cysteine. They have the ability to bind heavy metals and are crucial for maintaining metal detoxification and homeostasis.
comment un metal lourd peut mener à l’apoptose
f understanding the biochemical pathways involved in metal-induced carcinogenesis. In summary, the events that collectively lead to apoptosis during As toxicity include the generation of ROS, the accumulation of calcium ions, the upregulation of caspase-3, the downregulation of Bcl-2, and the deficiency of p53
que sont les étapes de l’apoptose
Que sont les étapes de la necrose
Que sont les heat shock proteins ?
Heat shock proteins (HSPs) are a group of proteins that are upregulated in response to stress, including exposure to metals.
These proteins play a crucial role in protecting cells from stress-induced damage and maintaining cellular homeostasis
