Lipids Flashcards
Classify simple lipids
Triglycerides- have alcohol glycerol
Waxes
Classify cpd lipids
Phospholipids- glycerophospholipid, sphingophospholipid
Glycolipid- cerebroside, ganglioside, globoside, sulfatide
Lipoprotein- chylomicron, VLDL, LDL, HDL
Classify and state the use of each type of phospholipid
Glycerophospholipid
Lecithin- contains choline- dipalmitoyl lecithin-lung surfactant that prevents the collapse of alveoli
Cephalin- contains ethanolamine- Thromboplastin contains mainly cephalins- blood coagulation
Phosphotidylinositol- contains myoinositol- 2nd messenger for oxytocine&vasopressin
Phosphotidylserine
Plamalogens- f.a of C1 of glycerol is linked by a ether bond instead of ester bond- in myelin& cardiac muscle- platelet activating factor
Lysophospholipid
Cardiolipin
Sphingophospholipid- alcohol sphingosine
Eg. Sphingomyelin- membrane of nerve tissue
Classify and state the function of each type of glycolipid
Cerebrosides- simplest glycolipid
Galactocerebroside-nerve tissue membrane
Glucocerebroside- non neural tissue
Sulfatide- ceramide +monosaccharide containing ester
Globoside- ceramide + oligosaccharide- determinants of ABO blood group system
Ganglioside- ceramide + oligosaccharide + N-acetyl neuraminic acid
State the Functions of the diff. Lipoproteins
Chylomicron- intestine- transport lipid from intestine to peripheral tissue
VLDL- liver- transport triacylglycerol from liver to peripheral tissue
LDL- plasma VLDL- transport cholesterol from liver to peripheral tissue
HDL- liver and intestine- transport free cholesterol from peripheral tissue to liver
What are eicosanoids synthesised from
Arachidonic acid
Examples of eicosanoids
Prostaglandins, thromboxanes, leukotriens
Classify prostaglandins
Classified depending on cyclopentane ring- A B C DE F G H I
Sub classifieds cording to no. Of double bonds in side chains
16 naturally occurring prostaglandins, 7 found in body
State the function of prostaglandins
Regulate synthesis of cAMP
Smooth muscle contraction and relaxation- pregnancy- promote uterine contraction
Inflammatory response- increase capillary permeability
Promote platelet aggregation
Decrease blood pressure
Elevate body temperature
Suppress gastric secretions
State the Functions of thromboxanes (TX)
TXA2
Produced by platelets- promotes platelet aggregation
Raises blood pressure- causes contraction of arterial wall smooth muscle
State the functions of leukotrienes (LT)
LT- Facilitate chemo taxis, inflammation, allergic reactions
LTC4, LTD4- contraction of lung muscles and constrict pulmonary airways - overproduction causes asthma
LTB4- attracts neutrophils and eosinophils to sites of inflammation
Definition of lipids
Organic substances that are insoluble in water but soluble in organic solvent such as chloroform
State the Functions of thromboxanes (TX)
TXA2
Produced by platelets- promotes platelet aggregation
Raises blood pressure- causes contraction of arterial wall smooth muscle
State the functions of leukotrienes (LT)
LT- Facilitate chemo taxis, inflammation, allergic reactions
LTC4, LTD4- contraction of lung muscles and constrict pulmonary airways - overproduction causes asthma
LTB4- attracts neutrophils and eosinophils to sites of inflammation
Classify fatty acids
Straight chain fatty acids- saturated, unsaturated
Branched chain f.a
Substituted f.a
Cyclic f.a
Functions of f.a
Building blocks for phospholipids and glycolipids
Derivatives serve as hormones
Serve as major fuel for most cells
What are essential f.a
Reqd for optimal health
Cannot be synthesised by body
Linoleic acid and linolenic acid
Arachidonic acid is synthesised from linolinic acid therefore in deficiency of linolenic acid, Arachidonic acid become essential
Functions of essential f.a
Synthesis of eicosanoids
Maintenance of structural integrity- imp. Constituents of phospholipids in cell membrane.
Development of retina in brain ( docohexaenoic acid )
Antiatherogenic effect- increase esterification and excretion of alcohol
What are micelles?
In aq. Systems- polar phospholipid- disperse to form micelles
Hydrocarbon tail of phospholipid hidden from aq. environment
Hydrophilic heads are exposed on the surface facing the aq. medium
What is a liposome?
artificially formed aq. vesicles enclosed by a lipid bilayer
Formed by- suspending phospholipid in aq. medium and sonicating ( agitating by high freqn sound waves)
Used to- study membrane permeability, deliver drugs to cells
What are detergents?
Amphipatic molecules that Form micelles in aq. Solution
Eg. Bile acids, bile salts
Function of cholesterol
Major structural constituent of cell
Precursor for: steroid hormones ( estrogen), bile acids, Vit D
Classify lipids
Simple- esters of fatty acids with various alcohols
Compound- esters of fatty acids with alcohols that have a prosthetic grp
Derived- obtained after hydrolysis of simple and cpd lipids
What are micelles?
In aq. Systems- polar phospholipid- disperse to form micelles
Hydrocarbon tail of phospholipid hidden from aq. environment
Hydrophilic heads are exposed on the surface facing the aq. medium
