Quick Revision Series

Biosynthesis of cholesterol- a quick revision

Biosynthesis of cholesterol The biosynthesis of cholesterol may be divided into five steps: (1) Synthesis of Mevalonate from acetyl-CoA. (2) Formation of Isoprenoid units from Mevalonate by loss of CO2. (3) Condensation of six isoprenoid units forms Squalene. (4) The cyclization of Squalene gives rise to the parent steroid, Lanosterol. (5)Formation of cholesterol from lanosterol.

Biosynthesis of cholesterol- a quick revision Read More »

Regulatory Mechanisms- Lipid Metabolism (summary Chart)

  Enzyme and pathway Effect of substrate concentration Allosteric Modification/ Feedback Inhibition/Covalent modification Induction/ Repression Clinical Significance Acetyl CoA Carboxylase (Fatty acid synthesis) Activity increases during the well-fed state Activity decreases during fasting Activator- Citrate, ATP Acetyl CoA Insulin- activates the enzyme by covalent modification of the enzyme (dephosphorylation through stimulating protein phosphatase enzyme) Inhibitors– Long-chain fatty

Regulatory Mechanisms- Lipid Metabolism (summary Chart) Read More »

×