Lipid peroxidation

Definition

Lipid peroxidation is a process in which free radicals attack lipids, particularly polyunsaturated fatty acids, leading to the formation of lipid hydroperoxides and other reactive species. This process is significant because it can cause cell membrane damage, alter membrane fluidity, and contribute to cellular apoptosis and necrosis. Understanding lipid peroxidation is crucial for grasping the impacts of reactive species generated by plasma on cellular structures and functions.

5 Must Know Facts For Your Next Test

1. Lipid peroxidation can initiate a chain reaction, causing extensive damage to cellular membranes if not properly regulated by antioxidants.
2. The accumulation of lipid peroxides can lead to the production of toxic byproducts that further exacerbate cellular damage and inflammation.
3. Increased lipid peroxidation is often associated with various diseases, including neurodegenerative disorders and cancer, highlighting its role in pathology.
4. Plasma treatment has been shown to influence lipid peroxidation levels in cells, suggesting that plasma can modulate oxidative stress and cell fate.
5. The end products of lipid peroxidation can serve as signaling molecules that may trigger apoptosis or necrosis in affected cells.

Review Questions

• How does lipid peroxidation relate to the mechanisms of cell death such as apoptosis and necrosis?
  • Lipid peroxidation contributes to both apoptosis and necrosis by damaging cell membranes and inducing oxidative stress. When lipids are oxidized, it leads to the formation of toxic byproducts that can trigger signaling pathways for programmed cell death (apoptosis) or uncontrolled cell death (necrosis). The extent of lipid peroxidation influences which pathway is activated, as moderate levels may lead to apoptosis while severe damage often results in necrosis.
• In what ways do reactive oxygen species (ROS) drive the process of lipid peroxidation in cellular membranes?
  • Reactive oxygen species (ROS) initiate lipid peroxidation by abstracting hydrogen atoms from unsaturated fatty acids within cell membranes. This creates lipid radicals that react with molecular oxygen to form lipid hydroperoxides. These hydroperoxides can decompose further into reactive aldehydes and other harmful compounds, perpetuating oxidative damage and affecting membrane integrity, fluidity, and function.
• Evaluate the role of antioxidants in mitigating the effects of lipid peroxidation on cellular health and survival.
  • Antioxidants play a critical role in protecting cells from the damaging effects of lipid peroxidation by neutralizing free radicals before they can cause significant harm. They help to restore balance by converting lipid hydroperoxides back into stable compounds or preventing their formation altogether. This protective action supports cellular health by maintaining membrane integrity and preventing premature cell death due to oxidative stress, thereby enhancing overall cell survival in the presence of harmful agents such as those generated during plasma treatment.

Related terms

Reactive Oxygen Species (ROS):

Highly reactive molecules that contain oxygen and can lead to oxidative stress, which damages various cellular components, including lipids.

Antioxidants: Molecules that can neutralize free radicals and reduce oxidative stress by preventing or repairing damage caused by lipid peroxidation.

Apoptosis:

A programmed cell death process that can be induced by oxidative damage, including lipid peroxidation, to eliminate damaged or harmful cells.