Biochemistry : Lipid Catabolism Intermediates

Study concepts, example questions & explanations for Biochemistry

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Example Questions

Example Question #21 :Lipid Catabolism

Phosphatidate is an intermediate in the synthesis of__________.

Possible Answers:

glycerophospholipids

triacylglycerols and glycerophospholipids

sphingolipids

Sterols

triacylglycerols

Correct answer:

triacylglycerols and glycerophospholipids

Explanation:

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 #773 :Biochemistry

Which product of the oxidation of fatty acids is an important intermediate in the citric acid cycle?

Possible Answers:

FADH₂

Fatty acyl-CoA

Acetyl-CoA

A fatty acyl-CoA two carbon atoms shorter in length

Succinyl-CoA

Correct answer:

Acetyl-CoA

Explanation:

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.

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