34. Cholesterol Synthesis. Main Metabolites. Regulation and Enzymes. Examples of Drugs - Inhibitors of Cholesterol Synthesis.
Walks through cholesterol synthesis from acetyl-CoA, moving through mevalonate, activated isoprenes, squalene and lanosterol to cholesterol, with HMG-CoA reductase as the rate-limiting enzyme. It then covers hormonal, phosphorylation-based and dietary control, the main cholesterol-derived metabolites such as bile acids, steroid hormones and vitamin D3, and finishes with statins and other drug classes that lower cholesterol.
Topic 34 of 76 in the MU Pleven syllabus for Biochemistry (Medicine, Year 2). The free AceMed note covers it in 5 sections, about 402 words (3 min of reading), with 14 flashcards.
In this note
Cholesterol Synthesis. Main Metabolites.
Cholesterol Synthesis
Main Metabolites Derived From Cholesterol
Regulation of Cholesterol Synthesis
Drugs that Inhibit Cholesterol Synthesis
Cholesterol Synthesis
1. Overview
Cholesterol is a 27-carbon, amphipathic lipid essential for:
Cell membrane structure and fluidity.
Synthesis of steroid hormones, bile acids, and vitamin D.
It is synthesized in all cells, but liver, intestine, adrenal cortex, and gonads are the most active.
2. Starting Material
Begins from Acetyl-CoA.
Acetyl-CoA is derived from:
Fatty acid oxidation
Glycolysis (via pyruvate → citrate shuttle)
Amino acid catabolism
3. Steps of Cholesterol Synthesis (Key Stages)
Step 1: Formation of Mevalonate (Rate-limiting Step)
