Unsaturated and Odd-Chain Fatty Acid Catabolism

This set of flashcards covers the oxidation pathways of unsaturated and odd-chain fatty acids, including key enzymes, structures, and metabolic consequences.

What is the main pathway for the complete oxidation of saturated fatty acids with an even number of carbon atoms?

The β-oxidation pathway.

What two additional enzymes are required for the oxidation of unsaturated fatty acids?

Δ3-enoyl CoA isomerase and 2, 4-dienoyl CoA reductase.

What is palmitoleic acid and how is it activated?

A 16-carbon mono unsaturated fatty acid activated by fatty acyl-CoA synthetase.

What happens to cis-Δ3-enoyl CoA during the oxidation of unsaturated fatty acids?

It is isomerized to trans-Δ2-enoyl CoA by Δ3-enoyl CoA isomerase.

What is the effect of a double bond on an odd-numbered carbon in fatty acid catabolism?

It generates a cis-Δ3-enoyl CoA which requires isomerization to proceed with β-oxidation.

What is linoleate and what is its structure?

A C18 polyunsaturated fatty acid with cis-Δ9 and cis-Δ12 double bonds.

How does the oxidation of polyunsaturated fatty acids differ from saturated fatty acids?

It involves additional steps with isomerization and reduction processes.

Which cofactor is essential for the conversion of methylmalonyl CoA to succinyl CoA?

Vitamin B12 (cobalamin).

What is a consequence of a vitamin B12 deficiency?

It results in pernicious anemia.

How are ketone bodies produced in the body?

Through a process called ketogenesis, primarily in the liver, when acetyl CoA condenses to form acetoacetyl CoA.

What is the significance of succinyl CoA in the metabolism of odd-numbered fatty acids?

It enters the citric acid cycle and can be used for glucose synthesis.

What role do ketone bodies play in energy metabolism?

They serve as a fuel source for many tissues, including muscles and the brain, especially during starvation.

How does diabetes mellitus lead to the formation of ketone bodies?

High blood glucose levels deplete oxaloacetate, leading to increased fatty acid catabolism and ketogenesis.

What determines the amount of ATP formed per round of beta-oxidation

whether the double bond originates on an odd or even numbered carbon

what is not generated when the double bond occurs on an odd number?

odd number does NOT generate an FADH2

Difference in ATP production between odd and even numbered carbon double bonds

Carbon double bonds on ODD numbers will generate 1.5 LESS ATPs