The synthesis of cholesterol involves several key stages:
1. Acetyl-CoA to Mevalonate: The process begins in the cytoplasm with the conversion of acetyl-CoA into mevalonate via the enzyme HMG-CoA reductase. This step is crucial and highly regulated. 2. Mevalonate to Isoprenoids: Mevalonate is then converted into isoprenoid units. This involves several phosphorylation steps. 3. Isoprenoids to Squalene: Six isoprenoid units condense to form squalene. 4. Squalene to Lanosterol: Squalene undergoes a cyclization reaction to form lanosterol. 5. Lanosterol to Cholesterol: Finally, lanosterol undergoes several enzymatic transformations to become cholesterol.
