Lipids Flashcards
What is a biological lipid?
A class of biological compounds that are generally insoluble in water, but soluble in organic solvents (hydrophobic)
What are some functions of lipids? (11)
Energy storage, insulation, protection of organs, water repulsion, inflammation, digestion, chemical signalling, antioxidants, membrane structure, coenzymes, pigments
What are fatty acids? Describe their 2 components.
Major lipids used to make other lipids. Fatty component-hydrocarbon chain. Acid component-carboxyl group (COO-).
What are saturated fatty acids?
Fatty acids with no double carbon bonds in the hydrocarbon chain (C=C).
What are monounsaturated fatty acids? Describe the shape.
Fatty acids with 1 double bond in the hydrocarbon chain. This causes a kink in the HC chain.
What are polyunsaturated fatty acids?
Fatty acids with multiple double bonds between carbons.
What type of fatty acid is arachidonic acid? Is it pro or anti-inflammatory?
Omega 6 fatty acid, which is pro-inflammatory
Are omega 3 fatty acids pro or anti-inlflammatory?
Anti-inflammatory
What are three arachidonic acid derivatives?
Prostaglandins, thromboxanes, leukotrienes
What are prostaglandins for?
Renal blood flow, mucosal protection, inflammation and fever
What are thromboxanes for?
Blood clotting
What are leukotrienes for?
smooth muscle contraction (tightening) in lungs and inflammation
Which enzyme breaks down cell membrane phospholipids into arachidonic acid?
Phospholipase A2
Describe the effect of corticosteroids on the arachidonic acid pathway.
Phospholipase A2 is inhibited, so the cyclooxygenase pathways 1 and 2 are inhibited, production of prostaglandins and thromboxanes are inhibited, so less inflammation
Describe the effect of NSAIDS on the arachidonic acid pathway.
It inhibits COX 1 and COX 2, so production of prostaglandins and thromboxanes (mainly COX 2 pathway) is inhibited
