Editing Glycolysis (section)

===Conversion of carbohydrates into fatty acids and cholesterol===
The pyruvate produced by glycolysis is an important intermediary in the conversion of carbohydrates into [[fatty acids]] and [[cholesterol]].<ref name=stryer2>{{cite book | vauthors = Stryer L | title = Biochemistry |chapter= Fatty acid metabolism. |edition= Fourth |location= New York |publisher= W.H. Freeman and Company|date= 1995 |pages= 603–628 |isbn= 0-7167-2009-4 }}</ref> This occurs via the conversion of pyruvate into [[acetyl-CoA]] in the [[mitochondrion]]. However, this acetyl CoA needs to be transported into cytosol where the synthesis of fatty acids and cholesterol occurs. This cannot occur directly. To obtain cytosolic acetyl-CoA, [[Citric acid|citrate]] (produced by the condensation of acetyl CoA with [[Oxaloacetic acid|oxaloacetate]]) is removed from the [[citric acid cycle]] and carried across the inner mitochondrial membrane into the [[cytosol]].<ref name=stryer2 /> There it is cleaved by [[ATP citrate lyase]] into acetyl-CoA and oxaloacetate. The oxaloacetate is returned to mitochondrion as malate (and then back into oxaloacetate to transfer more acetyl-CoA out of the mitochondrion). The cytosolic acetyl-CoA can be carboxylated by [[acetyl-CoA carboxylase]] into [[Malonyl-CoA|malonyl CoA]], the first committed step  in the  [[Fatty acid synthesis|synthesis of fatty acids]], or it can be combined with [[acetoacetyl-CoA]] to form 3-hydroxy-3-methylglutaryl-CoA ([[HMG-CoA]]) which is the rate limiting step controlling the [[Mevalonate pathway|synthesis of cholesterol]].<ref name=stryer4>{{cite book | vauthors = Stryer L | title = Biochemistry |chapter= Biosynthesis of membrane lipids and steroids. |edition= Fourth |location= New York |publisher= W.H. Freeman and Company|date= 1995 |pages= 691–707 |isbn= 0-7167-2009-4 }}</ref> Cholesterol can be used as is, as a structural component of cellular membranes, or it can be used to synthesize the [[Steroid#Steroidogenesis|steroid hormones]], [[Bile acids|bile salts]], and [[vitamin D]].<ref name=voet /><ref name=stryer2 /><ref name=stryer4 />