lipids qualitative. lipids are the body’s principal energy reserve. about 85% of the deaths caused...
TRANSCRIPT
Lipids Qualitative
• Lipids are the body’s principal energy reserve.• About 85% of the deaths caused by
cardiovascular disease are due to arteriosclerosis
• Lipids play vital roles both functionally and structurally in our bodily processes.– Insulate
Classification of lipids
• Simple lipids, compound lipids, steroids, terpenes,
Classification of Clinically Important lipids
Simple lipids
• Include;– Fats, oils, and waxes
The general structural formula for fats and oils
• Saturated– Rich energy reserves
• Unsaturated– Unsaturated fatty acids twist and bend• Inhibits close packing• Membrane fluidity
Compound Lipids
• Include – Phospholipids, sphingolipids, & glycolipids.
A typical phospholipid
• Phospholipids can be classified according to the alcohol esterified to the phosphate group.– Lecithins – Cephalins
• Components of cell membranes
Steroids
• Common structure – A 17-carbon 4-fused ring system
• The modifications include– Ring substituents• Hydrocarbon chains, hydroxyl groups, carbonyl groups
& Other modifications include double bonds
The steroid ring system
Cholesterol
• Cholesterol – the most abundant steroid in the body– a major component of cellular membran– an important precursor – Associated with atherosclerosis
• In order for lipids to be transported by the blood they must be complexed with water-soluble proteins known as lipoproteins
Generalized structure of a plasma lipoprotein
Identifying Lipids
• by Their Physical Properties – Solubility Test • Hydrocarbon content• The relative amounts of charged groups• The ionic character
– Altered by changes in solvent pH
– Emulsification Test
• chemical reactions to determine the presence of general structural features of lipid molecules
• Saponification Test for Triglycerides
• Halogenation Test for Unsaturated Lipids – Addition reaction• Hydrogenation
– Oils, changed to fats
• Liebermann–Burchard Test for Cholesterol– The Liebermann– Burchard reagent, a mixture of
acetic anhydride & sulfuric acid
• Ammonium Molybdate Test for Phosphate
• The yellow ammonium molybdophosphate precipitates from the reaction mixture
• the physical properties that are characteristic of lipids as a general class of compounds
• Chemical reactions– Determine specific structural information about
individual lipids