fatty acid

Examples of fatty acid in the following topics:

• Lipid Molecules

  • Fatty acids may be saturated or unsaturated.
  • Oleic acid is an example of an unsaturated fatty acid.
  • Essential fatty acids are fatty acids required for biological processes, but not synthesized by the human body.
  • Omega-3 fatty acid, or alpha-linoleic acid (ALA) , falls into this category and is one of only two fatty acids known to be essential for humans (the other being omega-6 fatty acid, or linoleic acid).
  • Alpha-linolenic acid is an example of an omega-3 fatty acid.

• Fatty Acids

  • The common feature of these lipids is that they are all esters of moderate to long chain fatty acids.
  • Acid or base-catalyzed hydrolysis yields the component fatty acid, some examples of which are given in the following table, together with the alcohol component of the lipid.
  • Natural fatty acids may be saturated or unsaturated, and as the following data indicate, the saturated acids have higher melting points than unsaturated acids of corresponding size.
  • The higher melting points of the saturated fatty acids reflect the uniform rod-like shape of their molecules.
  • The cis-double bond(s) in the unsaturated fatty acids introduce a kink in their shape, which makes it more difficult to pack their molecules together in a stable repeating array or crystalline lattice.

• Lipids: Sources, Uses in the Body, and Dietary Requirements

  • Humans and other mammals require fatty acids such as linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid), because they cannot be synthesized from simple precursors in the diet.
  • Both omega-6 and omega-3 are 18-carbon polyunsaturated fatty acids that differ in the number and position of their double bonds.
  • Fish oils are especially rich in the longer-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) .
  • Docosahexaenoic acid (DHA) is an omega-3 fatty acid.
  • DHA concentrations in breast milk range from 0.07-1.0% of total fatty acids and are influenced by the amount of fatty fish in the mother's diet.

• Lipid Metabolism

  • Fatty acids are the building blocks of lipids.
  • The fatty acid structure (see below) is one of the most fundamental categories of biological lipids.
  • Activation: Before fatty acids can be metabolized, they must be "activated. " This activation step involves the addition of a coenzyme A (CoA) molecule to the end of a long-chain fatty acid, after which the activated fatty acid (fatty acyl-CoA) enters the β-oxidation pathway.
  • A fatty acid is a carboxylic acid with a long aliphatic tail that may be either saturated or unsaturated.
  • The molecule shown here is the eight-carbon saturated fatty acid known as octanoic acid (or caprylic acid).

• Organic Acid Metabolism

  • Many bacteria are capable of utilizing fatty acids of various tail lengths as sole energy and carbon sources.
  • This process requires the β-oxidation pathway, a cyclic process that catalyzes the sequential shortening of fatty acid acyl chains to the final product, acetyl-CoA.
  • Fatty acid chains are converted to enoyl-CoA (catalyzed by acyl-CoA dehydrogenase).
  • The fatty acid chain that is left over after the thiolation step can then reenter the β-oxidation pathway, which can cycle until the fatty acid has been completely reduced to acetyl-CoA.
  • Free fatty acids are broken down to acetyl-CoA by dedicated enzymes in the β-oxidation pathway.

• Lipid Biosynthesis

  • This involves the synthesis of fatty acids from acetyl-CoA and the esterification of fatty acids in the production of triglycerides, a process called lipogenesis.
  • Fatty acids are made by fatty acid synthases that polymerize and then reduce acetyl-CoA units.
  • The synthesis of unsaturated fatty acids involves a desaturation reaction, whereby a double bond is introduced into the fatty acyl chain.
  • The doubly unsaturated fatty acid linoleic acid as well as the triply unsaturated α-linolenic acid cannot be synthesized in mammalian tissues, and are therefore essential fatty acids and must be obtained from the diet.
  • Outline the characteristics and processes of lipid biosynthesis, including:; lipogenesis and fatty acid biosynthesis

• Carboxylic Acid Natural Products

  • Carboxylic acids are widespread in nature, often combined with other functional groups.
  • The fatty acids are important components of the biomolecules known as lipids, especially fats and oils.
  • A mnemonic phrase for the C10 to C20 natural fatty acids capric, lauric, myristic, palmitic, stearic and arachidic is: "Curly, Larry & Moe Perform Silly Antics" (note that the names of the three stooges are in alphabetical order).
  • Interestingly, the molecules of most natural fatty acids have an even number of carbon atoms.
  • The following formulas are examples of other naturally occurring carboxylic acids.

• Connecting Lipids to Glucose Metabolism

  • Like sugars and amino acids, the catabolic pathways of lipids are also connected to the glucose catabolism pathways.
  • Triglycerides, a form of long-term energy storage in animals, are made of glycerol and three fatty acids.
  • Animals can make most of the fatty acids they need.
  • Fatty acids are catabolized in a process called beta-oxidation that takes place in the matrix of the mitochondria and converts their fatty acid chains into two carbon units of acetyl groups, while producing NADH and FADH2.
  • The acetyl groups are picked up by CoA to form acetyl CoA that proceeds into the citric acid cycle as it combines with oxaloacetate.

• Clostridial and Propionic Acid Fermentation

  • Acetogenesis is a biological reaction wherein volatile fatty acids are converted into acetic acid, carbon dioxide, and hydrogen.
  • Acidogenesis is a biological reaction wherein simple monomers are converted into volatile fatty acids.
  • Acetogenes is a biological reaction wherein volatile fatty acids are converted into acetic acid, carbon dioxide, and hydrogen .
  • The hydrolyzed compounds are fermented into volatile fatty acids (acetate, propionate, butyrate, and lactate), neutral compounds (ethanol, methanol), ammonia, hydrogen and carbon dioxide.
  • Acetic acid is equally a co-metabolite of the organic substrates' fermentation (sugars, glycerol, lactic acid, etc.) by diverse groups of microorganisms, which produce different acids:

• Pyruvic Acid and Metabolism

  • Pyruvic acid (CH3COCOOH) is an organic acid, a ketone, and the simplest of the alpha-keto acids.
  • Pyruvic acid (CH3COCOOH; is an organic acid, a ketone, and the simplest of the alpha-keto acids.
  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.
  • Pyruvate can be converted into carbohydrates via gluconeogenesis, to fatty acids or energy through acetyl-CoA, to the amino acid alanine, and to ethanol.
  • Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or to fatty acids through acetyl-CoA.