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| lipid containing food |
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| Lipid & it's Classification |
Definition Lipid & it's Classification
Definition: Lipids are a heterogeneous group of compounds, including fats, oils, steroids, wax and related compounds, which are related more by their physical than by their chemical properties.
Lipids may be regarded as organic substances relatively insoluble in water, soluble in organic solvents (alcohol, ether etc.), actually or potentially related to fatty acids and utilized by the living cells.
CLASSIFICATION:
Lipids may be regarded as organic substances relatively insoluble in water, soluble in organic solvents (alcohol, ether etc.), actually or potentially related to fatty acids and utilized by the living cells.
CLASSIFICATION:
Lipids are broadly classified into simple, complex and derived, which are further subdivided into different groups.
1. simple lipid: these are esters of fatty acids with various alcohols.
(a)fats and oils: esters of fatty acids with glycerol. The difference between fat and oil is only physical. Thus, oil is a liquid while fat is a solid at room temperature.
(b)waxes: esters of fatty acids(usually long chain)with alcohols other than glycerol. these alcohols may be aliphatic or alicyclic. cetyl alcohol is most commonly found in waxes.
2. compound/complex lipid: esters of fatty acids containing groups in addition to an alcohol and a fatty acid.
(a)phospholipids: lipids containing, in addition to fatty acids and an alcohol, a phosphoric acid residue.they frequently have nitrogen containing bases and other substituents, e.g. in 'glycerophopholipids' the alcohol is glycerol and in 'sphingo -phospholipids' the alcohol is sphingosine.
(b)glycolipids: lipids containing a fatty acid, sphingosine, carbohydrate and nitrogenous base. glycerol and phosphate are absent e.g.cerebrosides, gangliosides.
(c)lipoproteins: macromolecular complexes of lipids with protein.
(d)other complex lipids : lipids such as sulfolipids, and amino lipids.
3.precursor and derived lipids: these include fatty acids ,glycerol, steroids, other alcohols, fatty aldehydes, and ketone bodies, hydrocarbones, lipid-soluble vitamins and hormones.
1. simple lipid: these are esters of fatty acids with various alcohols.
(a)fats and oils: esters of fatty acids with glycerol. The difference between fat and oil is only physical. Thus, oil is a liquid while fat is a solid at room temperature.
(b)waxes: esters of fatty acids(usually long chain)with alcohols other than glycerol. these alcohols may be aliphatic or alicyclic. cetyl alcohol is most commonly found in waxes.
2. compound/complex lipid: esters of fatty acids containing groups in addition to an alcohol and a fatty acid.
(a)phospholipids: lipids containing, in addition to fatty acids and an alcohol, a phosphoric acid residue.they frequently have nitrogen containing bases and other substituents, e.g. in 'glycerophopholipids' the alcohol is glycerol and in 'sphingo -phospholipids' the alcohol is sphingosine.
(b)glycolipids: lipids containing a fatty acid, sphingosine, carbohydrate and nitrogenous base. glycerol and phosphate are absent e.g.cerebrosides, gangliosides.
(c)lipoproteins: macromolecular complexes of lipids with protein.
(d)other complex lipids : lipids such as sulfolipids, and amino lipids.
3.precursor and derived lipids: these include fatty acids ,glycerol, steroids, other alcohols, fatty aldehydes, and ketone bodies, hydrocarbones, lipid-soluble vitamins and hormones.
Reference : Biochemistry by U. Satyanarayana and Harper's Illustrated Biochemistry 26th edition.
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| This post is submitted by Fariha Fardous. 2nd year,Food & Nutrition Department. |
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