How does the catabolism of odd-chain fatty acids differ from the catabolism of even chain fatty acids?
The only difference is the final product that is produced. In the case of even chain fatty acids, we generate acetyl CoA molecules. But in the case of odd chain fatty acids, we generate acetyl CoA as well as a propionyl CoA molecule.
How are odd-chain fatty acids metabolized?
Metabolism. Oxidation of odd-carbon fatty acids requires three additional enzymes. This enzyme is responsible for carboxylating the α-carbon of a Propionyl-CoA to produce D-methylmalonyl-CoA. After this, methylmalonyl-CoA epimerase carries out an isomerization reaction.
How are odd-chain fatty acids formed?
In addition, odd chain fatty acids can be synthesized using propionyl CoA as the primer molecule in place of acetyl CoA and as products of even chain length fatty acids by alpha-oxidation. Propionyl CoA can also be carboxylated to D-methylmalonyl CoA by the enzyme propionyl CoA carboxylase (Fig. 14.8).
Why can odd-chain fatty acids produce glucose?
In the case where odd-chain fatty acids occur, such as in some plants and marine organisms a minor fraction of the products of β-oxidation of these acids is propionyl-CoA, which can, via succinyl-CoA, be converted to pyruvate and, thus, to glucose.
Are odd or even fatty acids better?
In the European Prospective Investigation into Cancer and Nutrition Study (EPIC) and the Norfolk Prospective Study, even-chain saturated fatty acid concentrations were associated with an increased risk of coronary heart disease, whereas odd-chain saturated fatty acid concentrations were associated with a decreased risk …
What are odd-numbered fatty acids?
Odd-numbered fatty acids are present in natural sources of animal or vegetable origin. Their concentration is generally not higher than 5% of the total fatty acids. In some cases, however, like in the mullet or Euglena gracilis, the value reaches 20% of the total fatty acids.
What types of products are formed during of fatty acids with an odd number of carbon atoms?
The oxidation of fatty acids with an odd number of carbon atoms proceeds by β-oxidation and yields, in addition to acetyl-CoA, one mole of propionyl-CoA per mole of fatty acid.
Which of the following is formed when odd-chain fatty acids undergo beta-oxidation?
Odd-chain fatty acids undergo beta-oxidation in the same manner as even chain fatty acids; however, once a five-carbon chain remains, the final spiral of beta-oxidation will yield one molecule of acetyl CoA and one molecule of propionyl CoA.
What is the fate of odd C fatty acids breakdown product propionyl-CoA?
Folate and Vitamin B12 Function Mitochondrial β-oxidation of dietary odd-chain fatty acids produces propionyl CoA in addition to acetyl CoA. Propionyl CoA is converted to D-methylmalonyl CoA in a reaction catalyzed by the biotin-dependent propionyl CoA carboxylase.
How are odd numbered fatty acids oxidized?
Odd-numbered fatty acids are broken down by β-oxidation to acetyl-CoA molecules and propionyl-CoA. Once the double bond is on the fourth carbon of the acyl-CoA at the beginning of a β-oxidation cycle it begins to be oxidized.
Can fatty acids be converted to pyruvate?
Carbohydrate synthesis from glycerol and fatty acids It can also not be converted to pyruvate as the pyruvate dehydrogenase complex reaction is irreversible. Instead the acetyl-CoA produced by the beta-oxidation of fatty acids condenses with oxaloacetate, to enter the citric acid cycle.
Do humans have odd-chain fatty acids?
The majority of research into fatty acid metabolism has been conducted primarily on even chain fatty acids (carbon chain length of 2–26) as these represent >99% of the total fatty acid plasma concentration in humans [11,12]. However there is also a detectable amount of odd-chain fatty acids in human tissue.
How does mitochondrial β-oxidation of dietary odd-chain fatty acids produce propionyl CoA?
Mitochondrial β-oxidation of dietary odd-chain fatty acids produces propionyl CoA in addition to acetyl CoA. Propionyl CoA is converted to D-methylmalonyl CoA in a reaction catalyzed by the biotin-dependent propionyl CoA carboxylase.
What are odd chain saturated fatty acids (OCS-FAS)?
Historically, odd chain saturated fatty acids (OCS-FAs) were used as internal standards in GC-MS methods of total fatty acids and LC-MS methods of intact lipids, as it was thought their concentrations were insignificant in humans.
Are odd-chain fatty acids found in Saccharomyces cerevisiae?
Odd chain fatty acids are uncommon in S. cerevisiae cultured in rich media, and therefore the fragment of m/z 241 is considered specific for phosphoinositol-containing lipids. Mitochondrial β-oxidation of dietary odd-chain fatty acids produces propionyl CoA in addition to acetyl CoA.
What is the shortest odd chain fatty acid?
The shortest odd chain fatty acid is propanoic acid (3:0) that plays several important biochemical roles, but, with the exception of platelet-activating factor, is rarely found esterified to lipids.