Which statement is true regarding the relationship between cholesterol and estrogen biosynthesis?

Which statement is true regarding the relationship between cholesterol and estrogen biosynthesis?

• A. Cholesterol is a precursor to estrogens.
• B. Cholesterol is not involved in estrogen synthesis.
• C. Aldosterone is the primary precursor of estrogens.
• D. Progesterone is the sole precursor of estrogens.

Answer: (A)

Cholesterol is the starting material for the production of all steroid hormones, including estrogens. In steroidogenic cells, cholesterol enters mitochondria and is converted to pregnenolone, the first step in the pathway. From there, the system builds toward progesterone and other intermediates, eventually forming androgens; these androgens are then converted to estrogens by the enzyme aromatase in tissues like the ovaries and adipose tissue. Because the estrogen molecules ultimately arise from the cholesterol backbone through these enzymatic steps, cholesterol is the precursor to estrogens. The idea that aldosterone is the primary precursor to estrogens isn’t correct, since aldosterone comes from a different branch of steroidogenesis and is not the main source of estrogens. Likewise, while progesterone is an important intermediate, it is not the sole precursor—estrogen biosynthesis requires further steps, including aromatization of androgens derived from cholesterol-derived pathways.

Cholesterol is the starting material for the production of all steroid hormones, including estrogens. In steroidogenic cells, cholesterol enters mitochondria and is converted to pregnenolone, the first step in the pathway. From there, the system builds toward progesterone and other intermediates, eventually forming androgens; these androgens are then converted to estrogens by the enzyme aromatase in tissues like the ovaries and adipose tissue. Because the estrogen molecules ultimately arise from the cholesterol backbone through these enzymatic steps, cholesterol is the precursor to estrogens.

The idea that aldosterone is the primary precursor to estrogens isn’t correct, since aldosterone comes from a different branch of steroidogenesis and is not the main source of estrogens. Likewise, while progesterone is an important intermediate, it is not the sole precursor—estrogen biosynthesis requires further steps, including aromatization of androgens derived from cholesterol-derived pathways.