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Question 505
Endocrinology → General
Classification
Question
SSBAQuestion Header
Which steroid hormone class has a 19-carbon nucleus?
Question Stem
Select the single best answer.
Options
A
Oestrogens
B
Glucocorticoids
C
Progestogens
D
Androgens
E
Mineralocorticoids
Explanation
Steroid hormones are derived from cholesterol and share a four-ring steroid structure. Oestrogens have an 18-carbon nucleus, androgens including testosterone have 19 carbons, while glucocorticoids, aldosterone and progesterone have 21 carbons.
Option Validity
A) Oestrogens have an 18-carbon nucleus.
B) Glucocorticoids have a 21-carbon nucleus.
C) Progesterone has a 21-carbon nucleus.
E) Aldosterone, a mineralocorticoid, has a 21-carbon nucleus.
Further Reading
Saxena, MRCOG-1 Basic Sciences, Endocrinology: Chemical Structure of Hormones, p. 300.