Flashcards
Lipids
Cards in this deck (22)
- 1Lipidsbiomolecules that partition into the organic solvent phase when we perform a two-phase extraction of a cell extract
- 2Triacylglycerols- 3 fatty acids attached to a glycerol through ester linkages
- majority of fatty acids in biological systems are found in this form
- major constituent of the body's depot fat - 3Simple Triacylglycerolssame fatty acid in all 3 positions
- 4Mixed Triacylglycerols2 or 3 different fatty acids
- 5Phospholipids- 2 fatty acids attached to a glycerol (which is also attached to a phosphate group - hydrophilic part of the molecule)
- structural elements of biological membranes - 6Glycolipids- contain both sugar and lipid portions
- important constituents of cell membranes
- e.g. blood group antigens - 7Lipoproteins- molecules made of proteins and fat
- are associated with cardiovascular health and disease
- e.g. LDL and HDL - 8Fatty Acids- building blocks of complex lipids
- central intermediates in metabolism
- rarely found in free form - 9Partial Hydrogenation- for unsaturated fatty acids
- used in manufacturing margarine and similar products
- can isomerize the double bonds generating “trans fats” - 10Trans Fat- unsaturated, synthetic fats believed to have serious negative effects on cardiovascular health
- trans double bond allows a given fatty acid to adopt an extended conformation - 11Carboxylic acids can combine with alcohols to form __________.Esters
- 12Carboxylic acids can combine with acids to form __________.Acid anhydrides
- 13Phosphoric acid (H3PO4) is a (1) _______ acid, meaning (2) __________?(1) triprotic
(2) it contains three ionizable hydrogen atoms per molecule
and at neutral pH it exists as an equilibrium mixture of H2PO4- and HPO42- - 14Phosphorylation- adds a -ve charge to molecules, leading to an increase in water solubility (e.g. Phospholipids, DNA,
RNA, many proteins) - 15Phosphoric acid can react with alcohols and acids to form _______ & _______ .Phosphate esters & phosphoanhydrides
- 16Glycerophospholipids- primary constituents of biological membranes
- amphiphathic meaning they combine both hydrophilic (head portion) and hydrophobic (tail) properties
- allows them to form lipid bilayers - 17Micelles- smallest and simplest lipid aggregate (diameters of ~ 3 – a few hundred nm)
- individual units are roughly spherical and wedge-shaped - 18Bilayers- since hydrophobic tails of phospholipids are too bulky to pack tightly together in micelles, they aggregate into bilayers
- individual units are cylindrical - 19Vesicles- bilayers spontaneously fold back on themselves to form liposomes or vesicles with diameters of 1 micron or more
- have interior aqueous cavities - 20Analysis of Lipids Through Two-Phase Extraction- organic solvent used for the extraction is mix of chloroform, methanol and H2O
- lipids in homogenized tissue separate into chloroform layer
- more polar molecules (proteins, sugars) partition into methanol/H2O layer
- once extracted, different types of lipids in the chloroform phase can be separated by adsorption chromatography - 21Trans-esterification- fatty acids linked through ester linkages to TAG and phospholipids break away to form new ester linkages with methanol when mixed in a warm solution of NaOH and methanol
- these methyl esters are more volatile - 22Adsorption Chromatographyseparates the different types of lipids (e.g. TAG and phospholipids)
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- 2 BIOC*2580 (Exam Review) Flashcards on Lipids, created by Erin Martin on 11/04/2016.
- Created by
- Erin Martin · Apr 2016
- Updated
- Apr 21, 2016
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