Lipids 1 Flashcards
Define lipids.
Heterogeneous organic molecules which are insoluble in water but soluble in organic solvents.
Where are lipids found?
Cell membranes
Lipid droplets in adipose tissue
Blood lipoproteins.
What are the 6 functions of lipids?
Stored form of energy Structural energy of membranes Enzyme cofactors Hormones Vitamins A, D, E and K Signalling molecules
Name the 5 classes of lipids.
Fatty Acids Triacylglycerols Phospholipids Glycolipids Steroids.
What are the 4 types of fatty acids?
Essential Fatty Acids - found in plants
Good Fats - high in polyunsaturated fatty acids
Bad Fats - high in saturated fatty acids, needed for myelination
Really Bad Fats - trans fatty acids, result from hydrogenation of vegetable oil
Define essential fatty acids.
Must be ingested. Arachidonic acid is a precursor of eicosanoids and can be synthesised from linoleic acid.
What can a deficiency of essential fatty acids result in?
Growth retardation, chronic intestinal diseases and depression.
Define triacylglycerols.
Esters of fatty acids and glycerol. Uncharged lipids which are water insoluble and necessary for dietary fuel.
Define phospholipids.
Composed of glycerol and are amphipathic. Hydrolysed to fatty acids and lysophospholipids.
Define bile salts.
Derivatives of cholesterol and act as biological detergents to form emulsions and mixed micelles.
Define cholesterol esters.
Make up 15% of dietary lipids and are digested to cholesterol and free fatty acids.
What is the process of the digestion of lipids?
Fat -> Emulsified fats -> Fatty Acids and Glycerol
What is steatorrhea?
Lipid malabsorption.
How are fatty acids transported around the body?
A solubilising protein is added and they’re packaged into chylomicrons which are released in to lymph then blood by exocytosis.
What is the enzyme which hydrolyses triacylglycerol?
Lipoprotein lipase.
