Lipids Flashcards
Palmitic acid
16:0; found in dairy
stearic acid
18:0; found in meat
oleic acid
18:1; found in vegetable oil
linoleic acid
18:2; omega 6; found in vegetable oils, corn, and soys
Linolenic acid
18:2; omega 3; found in grains and flax
arachadonic acid
20:4; omega 6; found in vegetable oils
eicosepenteneoic acid
20:5; omega 3; found in fish oil
docosehexanoic acid
22:6; omega 3; found in fish oil
phosphoglyceride/Glycerophospholipids
2 FA’s, glycerol, and a head group attached by a phosphate . derived from phosphatidic acid (PA; glycerol with phosphate on C3). Include phosphatidylcholine aka lecithin (main membrane phospholipids and surfactant component) and phosphatidylinositol (intracellular signaling)
dipalmitoyl phosphatidyl choline
major component in pulmonary surfactant; lecithin/sphingomyelin ratio (components of surfactant) is indicator of fetal development
Fatty acid length classes
<6=short chain, 6-12=medium chain, 13-20=long chain, and >22=very long chain. Length influences method of import: short and medium diffuse directly to hepatic portal vein for transport to liver, long chain fatty acid transport is facilitated by binding to albumin, dietary LCFA’s are transported by chylomicrons through the lymphatic and circulatory systems. MCFA’s and SCFA’s diffuse strait into mitochondria for β oxidation, while LCFA’s depend on carnitine shuttle to transport across inner membrane. VLCFA’s are oxidized in peroxisomes (note; Zellweger syndrome causes accumulation of VLCFA’s in blood because of peroxisome deficiency)
ceremide
sphingosine attached to unsaturated FA
Sphingophospholipids
ceremide+head group e.g. sphingomyelin (ceremide+phosphorylcholine)
Crerebrosides
ceremide + 1 sugar; mostly in brain
Sulfatidates
galactocerebroside + sulfate(s)
Globosides
ceremide + >1 sugar
Ganglioside
globoside + acidic sugar; 2 or more sugars to ceremide and broken down by hexosaminidases A and B. Tay-Sachs is cursed by Hexosamindase A deficiency and leads to accumulation of gangliosides in neurons
Eicosanoids
signalling molecules derived from 20C arachidonic acid. Released from membrane by phospholipase A2 and converted to eicosanoids by prostaglandin synthase and lipooxygenase
Prostaglandins
involved in inflammation response and have variety of effects; usually cause vasodialation, increased vascular permeability and edema
Thromboxanes
regulate platelet aggregation and vasoconstriction. PGI2 (prostacyclin) produced by endothelial cells interferes with thromboxane action
Leukotrienes
involved in inflammatory and hypersensitivity reactions. Production is mediated by PLA2, as well as phosphorylation and Ca2+ regulation of the enzymes involved in synthesis . They promote smooth muscle contraction (airway and intestines) , increase vascular permeability and edema, and some mediate chemotaxis
Hydroeicosatetraenoic acids (HETEs)
affect neutrophils and eosinophils; affect chemotaxis, stimulate adenylyl cyclase, and cause release of hydrolytic enzymes
Sphingomyelin
ceremide + phosphatidylcholine and is degraded by sphingomyelinase
Niemann-Pick
lipid storage disorder that results from the deficiency of a lysosomal enzyme, acid sphingomyelinase. The original description of NPD referred to what is currently termed NPD type A, which is a fatal disorder of early childhood characterized by failure to thrive, hepatosplenomegaly, and a rapidly progressive neurodegenerative course that leads to death by age 2-3 years.
Phospholipases
- A1: between C1 and FA
- A2: between C2 and FA
- C: between C3 and phosphate
- D: between phosphate and sugar/amino acid
