Lipids 1 Flashcards
What are the general characteristics of lipids?
Non polar molecules so hydrophobic
Lipids can contain certain hydrophilic groups - amphipathic lipids
Precise chemical structure of a lipid will determine its cellular function
Describe the difference between saturated and unsaturated fats;
Single C-C bond is saturated
Double C=C bond is unsaturated
Presence of a C=C double bond will distort the structure of the hydrocarbon chain
What is a fatty acid?
Fatty acid is a long carbon chain with carboxyl group attached COOH
Hydrocarbon chain is non polar/ hydrophobic and carboxyl group is polar/ hydrophilic
Describe the physical properties of fatty acids:
Van Der Waal’s forces are stronger when - hydrocarbons are longer and saturated
Melting temperature increases when hydrocarbon length increases
Melting temperature decreases when more C=C double bonds are present
Short chain length and unsaturation enhance the fluidity of fatty acids
What is the structural difference between fats and oils
Fats - triacylglycerol solid at room temperature, saturated fatty acids
Oils - triacylglycerol liquid at room temperature, unsaturated fatty acids
How is triacylglycerol broken down?
broken down by lipase
Individual lipases are required for each carbon glycerol so 3 are required
Lipases under the regulation of hormones, released when blood sugar level is low
Glycerol goes to the liver
Where does fatty acid metabolism occur?
In animals, fatty acid metabolism takes place in matrix of mitochondria and is termed Beta - oxidation
Describe lipid anabolism:
In animals, fatty acid synthesis takes place in cytosol and starting material is acetyl coA
This pathway makes saturated fatty acid with even numbers of C, catalysed by fatty acid synthases
Majority of fatty acids are synthesised from carbohydrates via the glycolytic pathway
Fatty acid synthase is positively regulated by high levels of insulin
