Fatty Acid Synthesis

Fatty acids are taken up by cells, where they may serve as precursors in the sythesis of other compounds
as fuels for energy production, and as substrates for ketone body sythesis
Ketones bodies may be exported to other tissues where they can be used for
energy production
Fats are an important source of dietary calories. Typically ___% of calories in the American diet are from fat.
Fat is the major form of energy storage. In a typical individual the fuel reserves are distributed as follows:
fat: 100,000 kcal

protein: 25,000 kcal

carbohydrate: 650 kcal

Fatty acids are intermediates in the sythesis of other important compounds. Examples include:
phospholipids (in membranes), Eicosanoids, including prostaglandins and leucotrienes, which play a role in physiological regulation
Some diseases involve disturbances in fatty acid metabolism. These include:
diabetes mellitus, specific disorders of fatty acid oxidation, such as Sudden Infant Death Syndrome and Reye Syndrome, which might be related to a deficiency of medium chain acyl CoA dehydrogenase, an important enzyme of fatty acid oxidation
Here are the major metabolic sources of acetyl CoA and some of the pathways for which it serves as a substrate
Acetyl CoA is at the center of lipid metabolism. It is produced from:
Fatty acids, glucose (through pyruvate), Amino acids, Ketone bodies
Acetyl CoA can be converted to fatty acids, which in turn give rise to:
triglycerides, phospholipids, eicosanoids, ketone bodies
Acetyl CoA is the precursor of cholesterol, which can be converted to:
steroid hormones, bile acids
Acetyl Co Metabolism produces energy, generated by the complete oxidation of acetyl CoA to
carbon dioxide and water through the tricarboxlic acid cycle and oxidative phosphorylation.
The structure of Acetyl CoA consists of two parts:
Acetyl group and Coenzyme A
Coenzyme A:
Beta-mercaptoethylamine, Pantothenic acid (not synthesized in man – an essential nutrient), phosphate, 3′,5′-adenosine diphosphate
Function of CoA
CoA is a commonly used carrier for activated acyl groups (acetyl, fatty acyl and others). The thioester bond which links the acyl group to CoA has a large negative standard free energy of hydrolysis (-7.5kcal/mole). This qualifies it as a high energy bond, and explains why an acyl group attached to CoA in this manner is considered to be activated.