Download Lipids: Classification, Structures, and Functions and more Quizzes Biochemistry in PDF only on Docsity!
What are the three general groups of
lipids?
Storage lipidsStructure lipidsOthers TERM 2
Storage lipids contains,
built
DEFINITION 2 Contains fatty acids and oilsBuilt to make them stable (i.e. inert) and easy to dissassemble TERM 3
Structural lipids contains,
built
DEFINITION 3 Contains phospholipids and steorsBuilt to provide stability and mobility for membrane components TERM 4
Other lipids contains,
built
DEFINITION 4 contains: cofactors, electron carriers, pigments, hydrophobic anchros, hormones, intracellularbuilt to provide special function TERM 5
Structural features of many lipids
lipids
DEFINITION 5 Backbones-sphingosine-glycerolFatty Acids (R-goups)- hydrocarbonsComplex rings-cholestoral and derivatives- cofctors-signaling molecules, -vitamines
Storage lipids (what kind of structure)
Fatty acid structure TERM 7
Fatty acid structure
DEFINITION 7 Hydrocarbon derivatives-carboxylic acids w/ hydrocarbon chains TERM 8
Hydrocarbon derivatives ( what atters, typical
range, may be/may contain)
DEFINITION 8 Length matters, how many double bonds matter(typical size ~4-36 carbons)May be:-fully or partly saturated-brancehd or unbranchedMay contain:-three carbon rings, and epoxide ( carbons and an oxygen w/ single bonds, residues, and R groups TERM 9
What are epoxide residues?
DEFINITION 9 2 carbons and an oxygen w/ single bonds TERM 10
Fatty acids double bonds arrangement, why?
DEFINITION 10 biological fatty acids DO NOT usually contain conjugated double bondsusually are separated by a methylene groupdouble blond, methylene, double bond Enzymes recognize the preferred structure, for increasing rate of reaction
Unsaturated vs Saturated
Unsaturated --> Oily- contain bends, double bonds create kinksSaturated --> Waxy- linear , stack up well TERM 17
What are the differences in unsaturated vs.
saturated based on?
DEFINITION 17 chain length # of C'sdouble bond characterbranched/unbranched TERM 18
What is the main group of storage lipids
called?
DEFINITION 18 Traiclyglycerols or triglycerols TERM 19
Triaclyglycerol components? Characteristics?
Function? Cleaved by/how?
DEFINITION 19 Clycerol + 3 fatty acidsEster linked fatty acidsHydrophogic, nonpolarNearly insolbule inw aterServe as storage forms of metabolic fuelCleaved by lipases: hydrolyze ester linkages TERM 20
Advantages of using triglycerols as fuels
DEFINITION 20
- hydrophobic- no need for hydration (.e. solvation layter)- saves energy2. carbon atoms highly reduced- yield more energy than carbohydrates through oxidation (that is, catabolic pathways)e.g. 15mg of triaclyglycerols = 1350 mg of glycogen
Waxes (composed of,
functions)
Esters of:Long chain (14-36 carbon) saturated/unsaturated fatty acids + Long chain (16-30 carbon) alcohols Melting points higher than triacylglycerols Waterproofers for feathers Prevent evaporation from holly, rhododendron, poison ivy Polishes and lotions Derived from palm, lanolin (sheeps wool), beeswax TERM 22
What are general terms/components of
membrane lipids (structural lipids)
DEFINITION 22 Phospholipids --> lipids with phosphates --> polar head + FA- some glycerophospholipids and sphingolipids with a polar group + fatty acidGlycolipids --> lipids with sugar-some sphingolipids wit ha simple sugar instead of a phosphate and galactolipids (sulfolipids) TERM 23
What are the three general classes of
membrane lipids/structure? Organized by?
DEFINITION 23 Organied by backbonesGlycerophospholipids/phosphoglyceridesSphingolipidsS TERM 24
What is a parent molecule?
DEFINITION 24 The simplest member of group of molecules TERM 25
Glycerophospholipid (structure, parent group)
DEFINITION 25 Glycerol backboneC1 - Fatty AcidC2- Fatty acidC3- Phosphate(phosphodiester bond) + polar head group (alcohol)Phosphatidic Acid
Glycosphinogolipids (found where, structure,
features, types/names)
bunches of sugarsMostly on the outer face of the plasma membranehead groups have one or more sugars on C1 of ceramideCerebrosides: one sugar on ceramideGlobosides: more tan one sugar on ceramideNo net charge @ pH 7 = Neutral glycoipid TERM 32
Glycosphingolipid and clinical/forenic
significance
DEFINITION 32 -form blood typesblood group antigens O,A, B --> based on difference in terminal sugar TERM 33
Sphingolipids and disease (name them)
DEFINITION 33 Tay Sachs diseaseGacuher's diseaseSandhoff's diseaseFabry's diseaseNiwemann-Pick disease TERM 34
Gangliosides (structure/composition)
DEFINITION 34 -polar head group = Oligosaccharides-one or more N- acetylneuraminic acids (a sialic acid) TERM 35
Galactolipids (structure, vs.
glycosophingolipids, located in, composition)
DEFINITION 35 different from glycosphingolipids: no nitrogenNo phosphate: plants conserve phsophateLocated in thylakoid membrannes of chloropolasts-most abundant membrane lipids on earth1, diacylglycerol --> glycerol w. acyl chains in number 1 and 2 positions, nothing on carbon 3+1 of 2 galactose at C3(2 FA +mono or disaccharide + SO4 - sulfolipid)
Sterols (structure, variations, produced from)
Rigid core of four fused hydrocarbon rings- ABCD ring in z form and branched side chainsSterol nucleus can also be- three 6-carbon rings, one 5 carbon ring, nearly planarProduced from acetate TERM 37
Sterols types of roles and general functions
DEFINITION 37 Passive role: structural lipidsActive roles: Diverse TERM 38
Sterols passive roles
DEFINITION 38 In nearly all cells BUT bacteriaCholesterol (type of sterol) is ampiphatic --> polar head group + non polar tailalters membrane fluidity and assists in lipid transport- at low temp: prevents hydrocarbon crystallization (e.g. adding cholesterol acting like unsaturated fatty acids wiggles in and gives lipids more mobility)- at high temp: decrease overall fluidity (e.g. adding cholesterol, TERM 39
Sterols active roles
DEFINITION 39 Steroid hormones are potent signals for gene expression, cause genes to be expressed --> act as regulatory moleculesBile Acids (derived from cholesterol) emulsify fats to make them more accessible for degredationPrecursors for vitamins and hormones (forms vitamins and hormones) TERM 40
Phosphatidylinositols (are, function,
reside)
DEFINITION 40 INTRAcellular signals and cofactorsFunction: second messengersResides in the plasma membrane- can become phosphorylated in several places-derivatives are second messangers
Eicosanoids how many classes, what are their
names?
Three classesProstaglandinsThromboxanesLeukotrienes TERM 47
Prostaglandins
DEFINITION 47 One 5-carbon ring Two groups with many subtypes PG E = ether-soluble PG F = phosphate (water) soluble Regulate cAMP synthesis through Adenylate Cyclase cAMP is a Second Messenger and a co-factor - TERM 48
What are the two groups of prostaglandins
DEFINITION 48 PG E = ether-solublePG F = phosphate (water) soluble TERM 49
Thromboxanes (structure, function, inhibition)
DEFINITION 49 One 6 carbon ringPRoduced by plateletsInvolved in platelet derived activites like clottingSynthesis is inhibited by non- steroidal anti-inflammatory drugs TERM 50
What anti-inflammatory drugs inhibit
thromboxane synthesis?
DEFINITION 50 Ibuprofen, aspirin, acetaminophen
Leukotrienes (function, structure, too much
can cause what)
Contain 3 conjugated double bonds Open (no cyclic) structure, linear structure Serve as signaling molecules Overproduction causes asthma attacks and contributes to anaphyllactic shock TERM 52
Steroid hormones (what are they, structure)
DEFINITION 52 Messengers between tisseusoxidized derivatives of sterol- sterol nucleus but no alkyl chian TERM 53
Steroid hormones movement through
body/cell, binding (what concentration best)
DEFINITION 53 Move through blood stream as complex w/ proteins- hydrophobic -
need hydrophilic compound to move through blood-Bind to specific receptors-Bind with high affinity: low concentrations have maximal effectsSteroid hormone diffuses through nonpolar membrane inside cell --> binds to receptor inducing conformational change --> hormone receptor binds to MAJOR groove on DNA --> induce change in gene activity TERM 54
Steroid hormones functions
DEFINITION 54 gender hormonesanti-inflammatory drugs-treat asthma and arthritis TERM 55
Vitamin A (what is it, name, derivatives, leads
to/essential for)
DEFINITION 55 hormone precursorRetinOLbiologically INactivederivatives are metabolic and cell regulators-retinoic acid regulates epithelial cell gene expression through nuclear receptorsWhen oxidized, results in retinal
Vitamin K (function, use, found in,
structure)
Undergoes oxidation-reduction rxns during prothrombin formation-enzyme that produces fibrin from fibrinogen0promotes clot formationfound in green plant leavesRING + HYDROCARBON TERM 62
In general, separation of mixtures in lipids
utilizes what?
DEFINITION 62 Differences in polarityDifferences in solubility in non-polar solvents TERM 63
Neutral lipids used in lipid
oxtractino
DEFINITION 63 ethyl ether chloroform or benzne TERM 64
Membrane Lipids used
in
DEFINITION 64 polar organic solvents (ethanol or methanol) TERM 65
What do organic solvents do in lipid
extraction?
DEFINITION 65 reduce weak interactions i.e. changing bonds changes structure
Method of lipid extraction in organic solvents
Extraction pull all lipids out of membrane Take a bit of tissue, put it into blender, grind it up in solution that is conducive for lipids coming out Pull out all lipids out (polar and nonpolar) Put a mixture of organic and non- organic solvents in order to pull all lipids out ( Chloroform: methanol: water 1: 2: 0.8) End up with ONE chemical phase Wanna seprate them add a litlte more water, more polar character change ratio Phase seperationCause Chloroform + lipids that are non polar go to bottom denser solution Aqueos solutions on top contain more polar lipids, proteins + sugar TERM 67
Adsorption chromatography is
DEFINITION 67 separation of lipids based on polarity TERM 68
Adsorption chromotography method
DEFINITION 68
- Column is packed with insoluble polar material (silica) 2. Sample is added Polar Lipids bind to the column Neutral Lipids do not bind to column 3. Column washed with solvents of increasing polarity Neutral lipids are eluted in the first wash (chloroform) Other lipids are eluted using solvents of increasing polarity Very polar or charges lipids are eluted with alcohols TERM 69
Thin Layer Chromatography (method, how
detected)
DEFINITION 69 Plate of glass coated with w/ silicasample is applied as a spot or line to the bottom of the platebottom of plate (up to the spot) is placed into solventsolvent rises into silica through capillary action (lipids seperate)lower the lipid affinity for the silica the more the lipid moveslipids detected w/ iodine vapors flourescence or specific dyes TERM 70
TLC downside
DEFINITION 70 -Can only say 3 diff lipids, dont know purity, could be 4 different lipids,couldhavesame migrationDon't know what lipids are
