What are lipids?
Lipids are defined as organic compounds, which are insoluble in water. In the human body, these molecules are synthesized in the liver. The good sources of lipids are abundantly found in butter, cheese, fried foods, ghee, oil, whole milk and also in some red meats.
Lipids are also called nonpolar molecules as they are soluble only in nonpolar solvents such as fats, grease, oils, etc.
There are two major types of lipids:
- Simple lipids –– Fats and waxes are examples of simple lipids.
- Complex lipids — Phospholipids and sphingolipids are examples of complex lipids.
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Significance of Lipids
Lipids play a very important role in the human body. They are the main source of energy, which provides energy and produces hormones in our body. They are the structural component of the cell membrane. These lipids are also involved in cell signalling, digestion and absorption of food.
Let have a look into the process of peroxidation of lipids
Peroxidation of lipids
Lipid peroxidation is the most significant process known to occur both in plants and animals. This process is considered as the main molecular mechanism, which is involved in causing the oxidative damage to cell structures and in the toxicity process that lead to cell death.
This is a chain reaction initiated by the addition of oxygen radicals, resulting in the oxidative damage to polyunsaturated fatty acids. This is a significant process, which involves:
- Consumption of oxygen.
- Formation and Propagation of lipid radicals.
- Rearrangement of the double bonds in unsaturated lipids.
- The eventual destruction of membrane lipids, with the production of a variety of breakdown products, including alcohols, alkanes, ethers, aldehydes and ketones.
The complete process of lipid peroxidation can be described in three different steps:
The fatty acid radical is produced.
The produced fatty acid radicals react readily with molecular oxygen, thereby creating a peroxyl-fatty acid radical and more new fatty acid radical.
The reaction of radicals with a non-radical produces another radical. This represents the chain reaction mechanism. The end products of lipid peroxidation are reactive aldehydes.
Importance of Lipid peroxidation
Lipid peroxidation or auto-oxidation of lipid is responsible not only for deterioration of foods, but it is also useful for damaging the tissues causing inflammatory diseases, angina, stroke, cancer, atherosclerosis and the ageing process in humans. Lipid peroxidation is a chain reaction providing a continuous supply of free radicals that initiate future peroxidation and thus has potentially devastating effects.
Free radicals are atoms or molecules that are highly reactive with other cellular structures.
These highly reactive molecular species are formed in the body under normal conditions and cause damage to the proteins, nucleic acids and lipids in cell membranes and plasma lipoproteins. Overall, free radicals can cause cancer, coronary artery disease and other autoimmune diseases.
Also Refer: Diseases and their types
This article concludes an introduction to Lipids, lipid peroxidation and its importance. To know more about Lipids, their types, functions, other related topics and important questions on lipid peroxidation, keep visiting our website at BYJU’S Biology.