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They can be fats oils or. Examples of such solvents include acetone and ether.
Ether chloroform acetone benzene and general insolubility in water.
What is the chemical structure of lipids. Structure and properties of two representative lipids. Both stearic acid a fatty acid and phosphatidylcholine a phospholipid are composed of chemical groups that form polar heads and nonpolar tails The polar heads are hydrophilic or soluble in water whereas the nonpolar tails are hydrophobic or insoluble in water. Lipid molecules of this composition spontaneously form aggregate.
Lipids as a class of compounds are insoluble in water but are soluble in other organic solvents. Examples of such solvents include acetone and ether. Waxes steroids phospholipids and fats are the most common types of lipid groups.
Fats have glycerol in addition to three fatty acids. The structure of the fatty acids determines whether or not the fat is considered saturated or unsaturated. Simple lipids contain a trihydric alcohol glycerol and long chain fatty acids.
The carboxyl groups of the fatty acids are ester-linked to the hydroxyl groups of glycerol. The fatty acids present in simple lipids have generally 16 or 18 carbon atoms and they may be saturated or unsaturated. Lipids are made of a triglyceride that is made from the alcohol glycerol plus fatty acids.
Additions to this basic structure yield great diversity in lipids. Over 10000 kinds of lipids have been discovered so far and many work with a huge diversity of proteins for cellular metabolism and material transport. Lipids are considerably smaller than proteins.
The lipids are a large and diverse group of naturally occurring organic compounds that are related by their solubility in nonpolar organic solvents eg. Ether chloroform acetone benzene and general insolubility in water. There is great structural variety among the lipids as will be demonstrated in the following sections.
You may click on a topic listed below or proceed page by page. The Chemical Classes of LipidsTheir Structure and Nomenclature. Lipids do not share any overall characteristic chemical structural similarity but they can nevertheless be categorized into subclasses according to structural similarities.
One system for categorizing major classes of lipids is listed in Box 6-1 emphasizing those that are directly and indirectly of nutritional importance. Cholesterol is an animal sterol found in the body tissues and blood plasma of vertebrates. It can be found in large concentrations within the liver spinal cord and brain.
Cholesterol is an important component of the membranes of cells providing stability. Fats and oils the most common lipids in food are triacylglyceride mixtures ie. Structures formed by the linking of three different or similar fatty acids to the tri-alcohol glycerol 16.
A fat is defined as a mixture of triacylglycerides which is solid or pasty at room temperature usually 20 C. Structure of lipids. There is a huge variety of different lipids and the chemical structure varies between each of them.
Because of this it is difficult to outline a general structure of a lipid. All lipids do however contain at least one hydrocarbon chain ie. Each cell and sub-cellular organelles are surrounded by a lipid bi-layer.
70 to 80 per cent are polar lipids and the remainder is mostly protein. The lipid part of the membrane is polar or amphipathic lipid largely phosphoglycerides some amounts of sphingolipids and a negligible amount of triacylglycerols. PI has a polar and non-polar region making the lipid an amphiphile.
Phosphatidylinositol is classified as a glycerophospholipid that contains a glycerol backbone two non-polar fatty acid tails a phosphate group substituted with an inositol polar head group. She holds a PhD. Molecules called lipids have long hydrocarbon chains that determine the way they act.
They can be fats oils or. The lipids can be classified according to the chemical structure into the large group of heterogenous compounds as the following. Simple lipids are divided into fats oils and waxes.
Complex lipids such as phospholipids.