Steroid Biosynthesis EXAM QUESTIONS WITH
CORRECT UPDATED ANSWERS.
______ IPP units makes vitamin D - CORRECT ANSWER✅✅✅6 IPP units makes vitamin D
________________ acts as a modulator of neurotransmitter signaling in the brain without being
converted to other steroids. It affects the_____________ (memory and learning). Treatment thought to
help in multiple neurological disorders - CORRECT ANSWER✅✅✅PREGNENOLONE acts as a
modulator of neurotransmitter signaling in the brain without being converted to other steroids. It
affects the NMDA GLUTAMATE RECEPTOR (memory and learning). Treatment thought to help in
multiple neurological disorders
(female) In early-mid follicular phase, what inhibits pituitary glands from producing FSH and LH? -
CORRECT ANSWER✅✅✅Progesterone
Estradiol
(female) In late follicular phase, what stimulates pituitary glands to produce FSH and LH? - CORRECT
ANSWER✅✅✅Estradiol
(male) what inhibits pituitary glands from producing FSH and LH - CORRECT ANSWER✅✅✅Inhibin
inhibits FSH
testosterone inhibits LH
17-alpha-hydroxyprogesterone can be made from progesterone and 17-alpha-hydroxypregnenolone via
what enzymes? - CORRECT ANSWER✅✅✅progesterone (17-α-hydroxylase)
17-alpha-hydroxypregnenolone (3-beta-hydroxysteroid dehydrogenase)
Calcitriol increases what? - CORRECT ANSWER✅✅✅-increase the absorption of Ca2+ and Phosphate
in intestinal cells
-increase the reabsorption of Ca2+ by the kidneys
-promote resorption of Ca2+ from bone
, *The resulting effect of calcitriol is an elevation in blood Ca2+ and Phosphate levels.
Cortisol have affinity for ______________and are __________times more concentrated than
mineralocorticoids - CORRECT ANSWER✅✅✅Cortisol have affinity for MINERALOCORTICOID
RECEPTORS and are 100 times more concentrated than mineralocorticoids
Explain how Cholecalciferol (vitamin D3), the inactive form of vitamin D is converted to Calcitriol - (1,25-
dihydroxycholecalciferol) - CORRECT ANSWER✅✅✅1. D3 produced in skin and intestinal cells
skin: 7-dehydrocholesterol cleaved via UV irradiation
intestinal cells: ergocalciferol (vitamin D2) converts
2. Liver: D3 (25-hydroxylase) -> 25-hydroxycholecalciferol
3. Kidneys: 25-hydroxycholecalciferol (1-alpha-hydroxylase) -> calcitriol
Explain how eating real licorice can lead to hypertension - CORRECT ANSWER✅✅✅Natural licorice
root contains isoflavones, which are inhibitors of 11beta-hydroxysteroid dehydrogenase which is
needed for metabolizing cortisol to cortisone as cortisone has a much lower affinity for the
mineralocorticoid receptor. Disruption of 11beta-hydroxysteroid dehydrogenase leads to more binding
of cortisol to mineralocorticoid receptor = salt retention = hypertension
How does cortisol suppress the immune system? - CORRECT ANSWER✅✅✅-induce i-kBa to inhibit
NF-kB which inhibits T cell proliferation
-promotes T cell apoptosis
-Decreased lL-2 and receptor lead to Inhibition of clonal expansion of B lympocytes
In the follicular phase, FSH and LF stimulate ___________ production in the ovaries? - CORRECT
ANSWER✅✅✅estradiol
In the Luteal phase, FSH and LH stimulates ___________ production in the ovaries? - CORRECT
ANSWER✅✅✅progesterone
Involuntary muscle contractions due to low blood calcium - CORRECT ANSWER✅✅✅Hypocalcamic
tetany
CORRECT UPDATED ANSWERS.
______ IPP units makes vitamin D - CORRECT ANSWER✅✅✅6 IPP units makes vitamin D
________________ acts as a modulator of neurotransmitter signaling in the brain without being
converted to other steroids. It affects the_____________ (memory and learning). Treatment thought to
help in multiple neurological disorders - CORRECT ANSWER✅✅✅PREGNENOLONE acts as a
modulator of neurotransmitter signaling in the brain without being converted to other steroids. It
affects the NMDA GLUTAMATE RECEPTOR (memory and learning). Treatment thought to help in
multiple neurological disorders
(female) In early-mid follicular phase, what inhibits pituitary glands from producing FSH and LH? -
CORRECT ANSWER✅✅✅Progesterone
Estradiol
(female) In late follicular phase, what stimulates pituitary glands to produce FSH and LH? - CORRECT
ANSWER✅✅✅Estradiol
(male) what inhibits pituitary glands from producing FSH and LH - CORRECT ANSWER✅✅✅Inhibin
inhibits FSH
testosterone inhibits LH
17-alpha-hydroxyprogesterone can be made from progesterone and 17-alpha-hydroxypregnenolone via
what enzymes? - CORRECT ANSWER✅✅✅progesterone (17-α-hydroxylase)
17-alpha-hydroxypregnenolone (3-beta-hydroxysteroid dehydrogenase)
Calcitriol increases what? - CORRECT ANSWER✅✅✅-increase the absorption of Ca2+ and Phosphate
in intestinal cells
-increase the reabsorption of Ca2+ by the kidneys
-promote resorption of Ca2+ from bone
, *The resulting effect of calcitriol is an elevation in blood Ca2+ and Phosphate levels.
Cortisol have affinity for ______________and are __________times more concentrated than
mineralocorticoids - CORRECT ANSWER✅✅✅Cortisol have affinity for MINERALOCORTICOID
RECEPTORS and are 100 times more concentrated than mineralocorticoids
Explain how Cholecalciferol (vitamin D3), the inactive form of vitamin D is converted to Calcitriol - (1,25-
dihydroxycholecalciferol) - CORRECT ANSWER✅✅✅1. D3 produced in skin and intestinal cells
skin: 7-dehydrocholesterol cleaved via UV irradiation
intestinal cells: ergocalciferol (vitamin D2) converts
2. Liver: D3 (25-hydroxylase) -> 25-hydroxycholecalciferol
3. Kidneys: 25-hydroxycholecalciferol (1-alpha-hydroxylase) -> calcitriol
Explain how eating real licorice can lead to hypertension - CORRECT ANSWER✅✅✅Natural licorice
root contains isoflavones, which are inhibitors of 11beta-hydroxysteroid dehydrogenase which is
needed for metabolizing cortisol to cortisone as cortisone has a much lower affinity for the
mineralocorticoid receptor. Disruption of 11beta-hydroxysteroid dehydrogenase leads to more binding
of cortisol to mineralocorticoid receptor = salt retention = hypertension
How does cortisol suppress the immune system? - CORRECT ANSWER✅✅✅-induce i-kBa to inhibit
NF-kB which inhibits T cell proliferation
-promotes T cell apoptosis
-Decreased lL-2 and receptor lead to Inhibition of clonal expansion of B lympocytes
In the follicular phase, FSH and LF stimulate ___________ production in the ovaries? - CORRECT
ANSWER✅✅✅estradiol
In the Luteal phase, FSH and LH stimulates ___________ production in the ovaries? - CORRECT
ANSWER✅✅✅progesterone
Involuntary muscle contractions due to low blood calcium - CORRECT ANSWER✅✅✅Hypocalcamic
tetany
