Metabolism of Acylglycerols and Sphingolipids Flashcards
What are two possible fates for Fatty acids?
Incorporation into triacylglycerides for storage
Incorporation into phospholipid components of cells
What is the beginning step for both fates of fatty acids?
Synthesis of Phosphatidate
How is Phosphatidate synthesized?
Two acyl chains are attached to glycerol-3-phosphate
C1 is usually saturated
C2 is usually unsaturated
How are triacyglycerides formed from phosphatidate?
Remove the phosphate
Add another FA chain
What is the key regulator in glyceroneogenesis?
PEP carboxykinase
How do glucocorticoids affect Type II diabetes?
Stimulate PEPCK in the liver to produce more triglycerides
Inhibit PEPCK in adipose tissues so newly synthesized triglycerides can’t be stored
Accumulation of FA in blood increases insulin resistance and disrupts the way muscles handle glucose
What are Thiazolidinediones?
New drugs for treating Type II diabetes
Stimulates PEPCK in adipose tissue
What are the four components of phospholipids?
Fatty Acid
Platform to attach FA - glycerol or sphingosine
Phosphate
Alcohol
What are the four steps required for phospholipid synthesis?
Synthesis of a backbone
Attachment of FAs
Addition of hydrophilic head group through a phosphodiester bond
Alteration of the head group
What is the role of CDP in phospholipid synthesis?
Required to activate either phosphatidate or the alcohol
What is combined to synthesize a phospholipid?
Diacylglycerol and activated alcohol
Activated diacylglycerol and alcohol
What is the most common phospholipid in mammals?
Phosphatidylcholine
How is phosphatidylcholine formed?
Methylation of phosphatidylethanolamine
How is phosphatidylserine formed?
Base exchange reaction with phosphatidylcholine or phosphatidylethanolamine
How is ceramide formed?
Condensation of Palmitoyl CoA and Serine
Reduction with NADPH
Addition of Acyl group
Desaturation with FAD
