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Example Questions
Example Question #1 : Lipid Catabolism Intermediates
Phosphatidate is an intermediate in the synthesis of __________.
sphingolipids
triacylglycerols and glycerophospholipids
triacylglycerols
glycerophospholipids
Sterols
triacylglycerols and glycerophospholipids
Phosphatidate is an intermediate in the synthesis of triacylglycerols and glycerophospholipids. This is simply because phosphatidate is the primary intermediate in lipid metabolism (which occurs in the synthesis of triacylglycerols and glycerophospholipids). More specifically, this intermediate is acylated to triacylglycerol through a fatty acid chain, and results in a glycerophospholipid product.
Example Question #2 : Lipid Catabolism Intermediates
Which product of the oxidation of fatty acids is an important intermediate in the citric acid cycle?
A fatty acyl-CoA two carbon atoms shorter in length
Succinyl-CoA
Acetyl-CoA
FADH₂
Fatty acyl-CoA
Acetyl-CoA
The correct answer is "Acetyl-CoA." The oxidation of fatty acids is activated by attachment to Coenzyme A to form fatty acyl-CoA, and the oxidation results in a shorter fatty acyl-CoA and acetyl-CoA. The acyl-CoA is oxidized in the citric acid cycle, where it is an important intermediate. Succinyl-CoA is also an intermediate in the citric acid cycle but is not a direct product of fatty acid oxidation. The shorter fatty acyl-CoA is oxidized further into FADH₂, but not as part of the citric acid cycle.