Introduction:
Lipids are group of compounds which are insoluble in water but soluble in organic solvents. Lipids are generally oily or greasy organic substances extractable from cells and tissues utilizing solvents such as chloroform or ether. Most abundant kind of lipid is triglyceride (Triacylglycerol).
Chemical composition of lipids:
Most of lipids contain fatty acids as their building blocks. Fatty acids are long chain organic acids (carboxylic acids). They contain carbon atoms from 4 - 36, a single (-COOH) carboxyl group and long non-polar tail that is responsible for water - insolubility and oily or greasy nature of most lipids.
Kinds of fatty acids:
Hydrocarbon tail of fatty acids may be either saturated, have one double bond (monounsaturated) or more (up to six) double bonds (polyunsaturated fatty acids). Double bonds are almost always in cis-configuration in unsaturated fatty acids. In polyunsaturated fatty acids double bonds are never conjugated (-CH - CH - CH = CH -), rather they are divided by methylene group (- CH =CH = CH2- CH = CH -). This arrangement is known as pentadiene structure.
Properties of fatty acids:
Similar to any other organic compound, fatty acids also contain their physical and chemical properties that are dependent on chemical nature of fatty acids.
Physical property of fatty acid:
Physical property of fatty acids is mainly determined by length of fatty acid and degree of unsaturation of hydrocarbon chain. Non polar hydrocarbon chains accounts for poor solubility of fatty acids in water. Longer the hydrocarbon chain and the fewer the double bonds the lower the solubility of fatty acids, e.g. Lauric acid with 12 carbon atoms contains greater solubility than Palmitic acid with 16 carbon atoms.
Melting points are also affected by length and degree of unsaturation of hydrocarbon chain. At room temperature (25oC), saturated fatty acids from 12 carbon to 24 carbon atoms have waxy nature, while unsaturated fatty acids of the chain length are oily liquids. This difference in melting points is because of deference in degree of packing of fatty acid molecules. For the given fatty acid chain, melting point reduces as number of double bond increases.
Chemical properties of fatty acid:
Nomenclature of fatty acids:
The general rule in nomenclature of fatty acids first considers number of carbon atoms, then number of double bonds if any and lastly position of double bonds counting from -COOH carbon as carbon number 1.
For instance, palmitic acid, CH3(CH2)14COOH, the saturated fatty acid is written as 16:0, that means fatty acid contains 16 carbon atoms and no double bonds .
Oleic acid, CH3(CH2)7CH=CH(CH)7COOH, is monounsaturated fatty acid is written as 18 : 1 (Δ9) that means fatty acid contains 18 carbon atoms and one double bond or carbon atom number 9. Notation (Δ) simple mean carbon atom number. For polyunsaturated fatty acid (PUFA) arachidonic acid, its nomenclature is written as 20:4 (Δ5,8,11,14), meaning that it is a 20 carbon atom fatty acid with double bond at positions/carbon atoms 5,8,11 and 14. It is significant to note that usually the cis configuration of double bonds in fatty acids is supposed when their nomenclatures are written.
Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring)
Expand your confidence, grow study skills and improve your grades.
Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring.
Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. Students work one-on-one, in real-time with a tutor, communicating and studying using a virtual whiteboard technology. Scientific and mathematical notation, symbols, geometric figures, graphing and freehand drawing can be rendered quickly and easily in the advanced whiteboard.
Free to know our price and packages for online biology tutoring. Chat with us or submit request at [email protected]
Groups must generally prepare a statement of cash flows which follows the same logic like the statement of financial position and income statement .
tutorsglobe.com budget constraint assignment help-homework help by online demand and supply tutors
Sign up for reliable Torts and Compensation Systems Assignment Help and get authentic papers to bag the best grades!
tutorsglobe.com industrial production of penicillin assignment help-homework help by online penicillin production tutors
Body organization of Astacus tutorial all along with the key concepts of Locomotion in astacus, digestive system and nutrition in astacus, Gaseous exchange in astacus, Excretory system in astacus
Polymer Solutions tutorial all along with the key concepts of Thermodynamics of Polymer Solution, Phase Equilibrium, Polymer solubility
Isolation-Structure Determination of Natural Products tutorial all along with the key concepts of General Methods of Extraction, Aqueous extraction of compounds, Fractionation, Fractionation by chromatography, Adsorption chromatography
www.tutorsglobe.com offers tabular design notation homework help, assignment help, case study, writing homework help, online tutoring assistance by computer science tutors.
Phylum Annelids tutorial all along with the key concepts of Coelomata-Eucoelomata, Features of Phylum Annelida, Classification of Phylum Annelida, Class Polychatea, Class Oligoachaeta and Class Hirudinea
Isomerism in complexes tutorial all along with the key concepts of Structural isomerism, facial and meridional isomers, Optical isomerism, Geometric isomerism
After decided on the point at which revenue is recognised, we can now twist to the subject of the recognition of expenses. The relevant convention in accounting is intended to give guidance regarding the recognition of expenses.
www.tutorsglobe.com offers answering questions to terms and balance of trade, economics assignment help - homework help and online tutoring by online trade economics tutor's help.
identification of the fault in a given tv receiver - very the tv receiver is switched on firstly. there is no picture just only blue retrace lines on the screen.
the cells that are created by apical meristem are distinguished into dissimilar types of permanent tissues.
tutorsglobe.com action of restriction enzyme assignment help-homework help by online recombinant dna technology tutors
1954130
Questions Asked
3689
Tutors
1482884
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!