Glycerides and Non-Glycerides lipids Flashcards
What are the recommended amounts of omega-3 fatty acids
at least 2 portions of fish per week, of which one should be oily.
2 portions of fish per week, one white and one oily, contain approximately 0.45g/d LC n-3 PUFA.
What are glycerides
they are lipid esters made of glycerol and fatty acids
What are the 2 classes of glycerides
Neutral glycerides - nonionic & nonpolar eg triglyceride
Phosphoglycerides - have a polar region, the phosphoryl group & a nonpolar fatty acid tail
What does esterification of glycerol with fatty acid make
a neutral glyceride and water
What does esterification make
mono, di and tri glycerides
What is a phosphoglyceride
they are phosphate esters that are charged and are central to the structure and function of cell membranes
Phosphate group = polar head (hydrophilic)
Alkyl chain of FA = nonpolar tail (hydrophobic)
What are sphingolipids
Not derived from glycerol - derived from sphingosine
a long chain, nitrogen containing alcohol and are the structural components of cellular membranes
what are sphingomyelins
phospholipids that are located throughout the body
Important for structural components of nerve cell membranes
Found in myelin sheath (25% are sphingomyelins) & insulate cells of the CNS
Essential to proper cerebral function & nerve transmission
what are glycosphingolipids
Also called glycolipids:
cerebrosides
sulfatides
gangliosides
Built on a ceramide backbone structure which is a fatty acid amide derivative of sphingosine
what are sterols
Lipids containing multiple rings of carbon atoms
Crucial components of cell membranes and many hormones
Manufactured in our bodies and therefore are not essential components of our diet
what are steroids
have a nucleus made of 4 fused 5 carbon rings e.g sex hormones
what is cholesterol
most abundant steroid and is amphipathic and found in large concentrations in the brain, spinal cord and liver
where is cholesterol synthesised from
acetic acid
where is cholesterol excreted from the liver as
bile
what is can cholesterol disease cause
Atherosclerosis; high blood pressure; coronary heart disease & others
how can cholesterol levels be reduced
Drugs: HMG-CoA reductase inhibitors (statins), such as lovastatin (Mevacor) and atorvastatin (Lipitor)
Regular exercise
what are complex lipids
Lipids that are bound to other types of molecules
Most important – plasma lipoproteins which are required to transport other lipids
4 major classes of human plasma lipoproteins
what are the 4 lipoproteins
- chylomicrons
- VLDL very low density lipoprotein
- LDL low density lipoprotein
- HDL high density lipoprotein
what are apolipoproteins
proteins synthesised in the liver that binds to lipids to form lipoproteins. They have a structural role and are co-factors for enzymes and have 6 classes: A,B,C,D,E,H
What bilayer does the plasma membrane have
a bilayer of phospholipids and is called the fluid mosaic model with a Hydrophilic phospholipid head (outside) and a hydrophobic tail (inside)
Why is is called fluid mosaic model
It is mosaic as Proteins and substances such as cholesterol become embedded in the bilayer, giving the membrane the look of a mosaic.
It is fluid as has a consistency of oil at body temperature which allows proteins and other substances to cross it.
what is embedded in the surface of fluid mosaic model
cholesterol - makes it more stable and stop solidifying when body temp is low
what chains attach to the outer surface of the plasma membrane
carbohydrate chains - they are specific to everyone and give people characteristics e.g blood type.
what are isoprene’s
Large diverse group of lipids – all compounds are built from 1 or more 5-carbon units called isoprene
Generic term = terpene
