Lipids Flashcards
Which are the classes of lipids?
1) Simple lipids -Includes fats and waxes which are esters of fatty acids with various alcohols.
2) Complex lipids -are esters of fatty acids containing groups in addition to an alcohol and one more fatty acid. they can be further divided into 3 groups.
3) Precursor derived lipids
Which are the three groups the Complex lipids?
- Phospolipids (lipids containing an alcohol and a phosphoric acid residue)
- Glycolipids, or Glycosphingolipids: contain a Fatty acid, a Sphingosine and a carbohydrate.
- Other complex lipids : such as Sulfolipids + lipoproteins etc.
What are neutral Lipids?
Uncharged lipids. Examples are : Acylglycerols, cholesterol and cholesteryl.
Which is the transport form of fatty acids in Plasa?
Free fatty acids, in body their found mainly as esters.
Which Fatty acids end with anoic in their names?
Saturated fatty acids.
How are the carbons of fatty acids named?
from carboxyl carbon as nr1
how many double bonds do saturated fatty acids have?
None
What are Eicosanoids?
compounds derived from eicosa (20 carbon) polyenoic fatty acid.
these comprise: Prostanoids, Leukotrienes (LTs) and Lipoxins (LXs)
Prostaglandins, prostacyclins and thromboxanes are…?
Prostanoids
which type of prostaglandin has a keto group in position 9
PGE (E type)
which fatty acids have anti inflammatory effects?
e3 Long chain fatty acids such as: alpha linoleic (ALA), EPa and DHA.
which compound is important as an intermediate in the synthesis of triacylglycerols and phosphoglycerols?
Phosphatedic acid. it is however not found in great quantities in tissues.
which are the most abundant phospholipids of the cell membrane?
Lecithins, glycerophospholipids containing choline.
What is the role of Dipalmitoyl lecithin?
Its a very effective surface-active agent and a major constituent of the surfactant, preventing adherence due to surface tension of the inner surfaces of the lungs.
What is the consequence of the absence of Dipalmitoyl in the lungs of infants?
causes respiratory distress syndrome.
Where does most phospholipids have their saturated acetyl radicals and their unsaturated acetyl radicals, respectively?
- Saturated acetyl radicals at the sn1 position
- Unsaturated acetyl radicals on the sn2 position of the glycerol.
Which lipid is involved in Apoptosis?
Phosphatidylserine.
Which lipids can be found in the cell membrane?
- Phosphatidylethnolalamine (cephalin)
- Phosphatidylserine
- Phosphatidylcholine
- Cholesterol
- Sphingomyelin (in outer leaflet)
What are lipid rafts and which lipids are particularly abundant there?
They are specialized areas of the plasma membrane where sphingomyelins are found.
Where are Sphingomyelins found and in which processes are they involved?
- Lipid rafts and myeline sheaths surrounding nerve fibers.
- Cell signalling and Apoptosis
What does sphingomyelins yield upon hydrolysis?
A fatty acid, Phosphoric acid, choline and sphingosine.
Sphingosine + Fatty acid = ?
Ceramide (also found in glycosphingolipids)
What role does the Phosphorylated Phosphatidylinositols?
They are minor components of the cell membrane and important components of both cell signalling and membrane trafficking.
Where can the Phosphotidylinositols have 1,2 or 3 phosphates attached?
Onto their inositol ring.
