Sex Hormone Synthesis & Action

Question 1

What is the rate limitng step for steroid hormone synthesis?

Answer 1

Steroidal acute regulatory protein (StAR)

Question 2

Which step in steroid hormone synthesis occurs in the mitochondria?
A. 3Beta-Hydroxysteroid dehydrogenation
B. 17-Hydroxylation
C. Aromatization
D. Synthesis of androstenedione
E. Synthesis of pregnenolone

Answer 2

E. Synthesis of pregnenolone

Question 3

Which one of hte following is a key intermediate for the synthesis of both testosterone and cortisol?
A. 7-Hydroxycholesterol
B. Aldosterone
C. Estradiol (E2)
D. Pregnenolone
E. Retinoic acid

Answer 3

D. Pregnenolone

Question 4

Which one of the following is true about testosterone?
A. It can be converted to a more active androgen at the target cell
B. It is synthesized from aldosterone
C. It is synthesized from estradiol (E2)
D. It mediates its action at target cells by binding to receptors on the cell surface
E. It stimulates the synthesis of gonadotropins (GnRH)

Answer 4

A. It can be converted to a more active androgen at the target cell

Question 5

Synthesis of which one of the follwoing hormones require the cooperation of two types of cells?
A. Androstenedio
B. Estradiol
C. DHEA
D. Pregnenolone
E. Progesterone

Answer 5

B. Estradiol

Question 6

Which one of the following proteins is not produced in the adrenal galnds?
A. 11β-Hydroxysteroid dehydrogenase
B. 17β-hydroxysteroid dehydrogenase
C. 21-Hydroxylase
D. Androstenedione
E. Steroidal acute regulatory (StAR)

Answer 6

B. 17β-hydroxysteroid dehydrogenase

the adrenal glands do not produce the
enzymes 17β-hydroxysteroid dehydrogenase and aromatase that are expressed in the gonads to produce androgens and estrogens

Question 7

Which ones of the following is only expressed in the adrenal glomerulosa cells?
A. 5alpha-Reductase
B. 11-Hydroxylase
C. 21-Hydroxylase
D. Aldosterone synthase
E. Aromatase

Answer 7

D. Aldosterone synthase

Question 8

Which one of the following enzymes is only expressed in the peripheral tissues?
A. 5alpha-reductase
B. 11-Hydroxylase
C. 21-Hydroxylase
D. Aldoesterone synthase
E. Aromatose

Answer 8

A. 5alpha-Reductase

Question 9

Which ones of the following hormone receptors do not belong in the same group as the others?
A. Androgen
B. Estrogen
C. Cortisol
D. Gonadotrphins
E. Thyroid hormones

Answer 9

D. Gonadotrphins

Question 10

All of the following hormones are encoded by POMC gene EXCEPT
A. ACTH
B. Beta-Endorphin
C. Y(gamma)-melanocyte stimulating hormone
D. Lipotrphins
E. Vasopresin

Answer 10

E. Vasopresin

proopiomelanocortin gene (POMC)