Steroid Hormones Oldies (Biochem Exam)

Choose true sentence (or sentences):
1. Reaction of dihydrotestosterone synthesis is catalyzed by 5α-reductase demands NADH
2. The plasma content of the DHT in adult male is one-tenth that of testosterone
3. estosterone is a product of the androstenedione reduction at the C 17 position
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Terms in this set (62)
Choose true sentence (or sentences):
1. Reaction of dihydrotestosterone synthesis is catalyzed by 5α-reductase demands NADH
2. The plasma content of the DHT in adult male is one-tenth that of testosterone
3. estosterone is a product of the androstenedione reduction at the C 17 position
2, 3
Dihydrotestosterone (DHT)
1. In many tissues DHT is the active form of testosterone
2. 400 µg secreted by testes
3. more potent than testosterone
1, 3
Dihydrotestosterone (DHT)
1. 50 to 100 µg secreted by testes
2. most significant product of testosterone
3. has hydride ion at carbon 6
1, 2, 3
Aromatization of androgens
1. demands O2
2. demands NADH
3. aromatization of androstenedione leads to estrone formation
4. peripheral aromatization of testosterone leads to estradiol formation
1, 3, 4
Aromatization of androgens
1. 3 Hydroxylation reactions
2. P450 monooxygenase included in aromatase enzyme complex
3. estrone formed from aromatization of testosterone
1, 2
Aromatization of androgens
1. 3 Hydroxylation reactions
2. P450 monooxygenase included in aromatase enzyme complex
3. estradiol formed from aromatization of testosterone
1, 2, 3
What is true
1. in Males peripheral aromatization of testosterone makes up 80% of estradiol production
2. theca cells are a source of androstenedione and testosterone
3. testosterone is an end product hormone
1, 2
What is true
1. females peripheral aromatization of androgens to estradiol makes up 50% of estradiol during pregnancy
2. corpus luteum source of progesteron
3. 17ß-estradiol is the primary estrogen of ovarian origin
1, 2, 3
What is correct
1. In pregnant women the production of estrone increases
2. The placenta is a source of estriol
3. in pregnant women the production of estriol increases
2, 3
Postmenopausal women
1. major source of estrogens is the conversion of androstenedione to estrone
2. increased aromatase activity prevents estrogenization
3. corpus luteum doesn't process enzymes necessary for conversion of progesterone to other steroid hormones
1, 3
CBG (Corticosteroid binding globulin) 1. produced in liver 2. cortisol binds less tightly to CBG than corticosterone 3. its synthesis is decreased by estrogens1CBG (Corticosteroid binding globulin) 1. produced in liver 2. cortisol binds more tightly to CBG than corticosterone 3. its synthesis is increased by estrogens1, 2, 3Transporten (CBG) 1. Aldosterone doesn't have specific plasma transport protein 2. Gonadal steroids bind very weakly to CBG 3. Progesteron binds more tightly than cortisol1, 2, 3Synthesis of SHBG (Sex-hormone-binding globulin) 1. is decreased in hypothyroidism 2. is increased by androgens 3. is decreased in advanced age1, 3SHBG 1. produced in liver 2. binds testosterone with specificity, high affinity, limited capacity 3. production increased by estrogens1, 2, 3SHBG 1. binds dihydrotestosterone with high affinity 2. women have 2x serum concentration of SHBG as man 3. increased in hypothyroidism1, 2What is true? 1. SHBG binds estrone with higher affinity than CBG 2. CBG binds progesterone with higher affinity than SHBG 3. CBG binds Estradiol with higher affinity than SHBG1, 2What is true? 1. SHBG binds estradiol with higher affinity than estrone 2. CBG binds corticosterone with higher affinity than cortisol 3. SHBG binds progesterone with higher affinity than CBG1, 2SHBG 1. also called testosterone-estrogen-binding globulin (TEBG) 2. men have more of it in serum 3. progesterone and cortisol have high affinity for SHBG1, 2Metabolic clearance rates of steroid 1. proportionally related to affinity of their binding SHBG 2. estrone cleared more rapidly than estradiol 3. estradiol cleared more rapidly than testosterone or DHT2, 3Metabolic clearance rates of steroid 1. inversely related to affinity of their binding SHBG 2. estrone cleared more rapidly than estradiol 3. testosterone cleared more rapidly than DHT1, 2, 3Choose true sentence (or sentences) describing the cortisol synthesis process: 1. hydroxylation at C11 position is relatively slow 2. hydroxylation at C11 position occurs before C21 hydroxylation 3. hydroxylation of 17a-hydroxyprogesterone at C21 position results in formation of 11-deoxycorticosterol1, 3Choose true sentence (or sentences) describing the cortisol synthesis process: 1. hydroxylation at C11 position is relatively slow 2. hydroxylation at C11 position occurs before C21 hydroxylation 3. hydroxylation of progesterone at C21 position results in 11-Deoxycorticosterone1, 3Mitochondrial enzymes are 1. 21 Hydroxylase 2. 11ß Hydroxylase 3. 17a Hydroxylase 4. 18 Hydroxylase 5. 18 Hydroxy-DH2, 4, 5Zona glomerulosa 1. Mitochondrial 18-hydroxylase present 2. doesn't have SER enzyme 17a-hydroxylase 3. corticosterone is hydroxylated to 18 hydroxycorticosterone1, 2, 3What is true 1. Mineralocorticoid synthesis - zona glomerulosa 2. Mineralocorticoid synthesis - zona reticularis 3. Glucocorticoid synthesis - zona fasciculata & reticularis 4. Glucocorticoid synthesis - zona glomerulosa & fasiculata 5. Androgen synthesis - zona glomerulosa 6. Androgen synthesis - zona reticularis1, 3, 6Which is / are in the SER 1. 1ß-hydroxylae 2. ∆ 5,4 isomerase 3. 21-hydroxylase2, 3Which is / are in the mitochondria 1. 1ß-hydroxylae 2. ∆ 5,4 isomerase 3. 21-hydroxylase1Choose and underline true or false: 1. About 50 to 100 µg of DHT are secreted by testes 2. Corticosterone has glucocorticoid activity 3. Most 17-hydroxypregnenolone follows the glucocorticoid pathway1, 2, 3Which is correct 1. 80% of estradiol produced in males comes from peripheral aromatization of testosterone 2. Dihydrotestosterone has 2 methyl groups in structure 3. Progesterone is converted to estriol in corpus luteum1, 2Which is true 1. Transcortin synthesis in liver is stimulated by estrogens 2. 50% of estradiol produced during pregnancy comes from aromatization of adrenal androgens 3. DHT is the strongest androgen secreted only by testis1, 2Which is true 1. in human males, the peripheral aromatization of testosterone is the source of 80% of produced estradiol 2. Testosterone as prohormone, is the substrate for synthesis of more active dehydroepiandrosterone 3. Most steroids with C17 hydroxyl group have more glucocorticoid and less mineralocorticoid action1, 3Choose true 1. 17a-hydroxypregnenolone is converted to dehydroepiandrosterone by 17ß-hydroxysteroid DH 2. 17ß-Hydroxysteroid DH converts oxygen at C17 of DHEA and androstenedione to hydroxyl group 3. ∆5 pathway ends with 17ß-OHSD1, 2Choose true 1. ∆4 pathway for conversion of pregnenolone to testosterone is the most used in human testes 2. testicular androgens synthesized in interstitial tissue by leidig cells 3. side chain cleavage enzyme P450scc is stimulated by ACTH in testes and ovaries1, 217-hydroxyprogesterone 1. substrate for 17,20 Lyase 2. can be synthesized from 17-hydroxypregnenolone 3. can not be substrate for corticosterone biosynthesis1, 2, 37-hydroxyprogesterone 1. substrate for 17,20 Lyase 2. can be synthesized from 17-hydroxypregnenolone 3. can not be substrate for 11-deoxycorticosterone synthesis1, 2, 3Aromatase 1. can use androstenedione as a substrate 2. contains cytochrome P450 3. involved in testosterone synthesis1, 2Which of the following statements are true: 1. androgens are excreted as 17-keto compounds 2. carbons 3,7,13 & 14 in the structure of cyclopentaperhydroepiandthrene are asymmetrical 3. dehydroepiandrosterene can be converted to delta-5-androstenediol1, 2, 3Aldosterone: 1. is synthesized from corticosterone in reversible reaction of 18-hydroxylase 2. in plasma is specifically bound with CBG 3. is the strongest natural mineralocorticoid3Aldosterone: 1. is synthesized from corticosterone in irreversible reaction of 18-hydroxylase 2. in plasma is specifically bound with CBG 3. is the strongest natural mineralocorticoid1, 3True statement 1. Aromatase activity is present in adipose tissue 2. 16a-hydroxylase catalyzes conversion of estron into 17beta-estradiol 3. Aldosterone is transported in plasma by highly specific transport protein1Which of these sentences are true: 1. dihydrotestosterone is the strongest androgen produced only by testes 2. aldosterone is transported in plasma by highly specific transporter plasma 3. dehydroepiandrosterone is one of the substrates of aromatasenoneChoose true 1. Cholesterol for synthesis of steroid hormones comes mainly from plasma 2.Cortisol in plasma bounded with protein is biological active fraction of this hormone 3. Bigger fraction of cortisol in plasma is bound by albumin1Conversion of pregnenolone to testosterone: 1. Need P45c17 2. in testis occur mainly by dehydroepiandrosterone pathway 3. 17,20-lyase is an enzyme of only progesterone pathway1, 2DHT (dihydrotestosterone) 1. Posess stronger biological activity than testosterone 2. during its synthesis NADPH is used 3. In men conversion of testosterone to DHT occurs mainly in testis1, 2Which are produced in mitochondria 1. Corticosterone 2. 11-deoxycortisol 3. testosterone 4. pregnenolone 5. aldosterone1, 4, 5Which are produced in adrenal zone fasciculata 1. pregnenolone 2. progesterone 3. corticosterone 4. 17beta-estradiol 5. testosterone1, 2, 3, 4, 5Which of the following statements are correct: 1. dehydroepiandrosterone has a double bond in position 4 of cyclopentanoperhydrophenanthrene 2. ndrostenedione is a major direct precursor of testosterone in humans 3. approximately 400 mg of dihydrotestosterone is produced daily2Which of the following statemens are correct:1.! Plasma SHBG concentrations in women is two times higher than in men 2. Gonadal steroid bind very weakly to CGB 3. in men In men estradiol is produced from testosterone predominantly by peripheral aromatization1, 2, 3True sentence are: 1. progesterone is synthesized as prohormone 2. cholesterol used in adrenal steroidogenesis mainly comes from plasma 3. 80% of 17beta - estradiol produced during pregnancy comes from aromatization of androgens2Aromatase enzyme complex 1. produces estrone using 17a-hydroxyprogesterone as a substrate 2. its activity is present in adipose tissue, liver, skin and ovaries 3. is composed from P-450 monooxygenase and 5a-reductase2Aldosterone 1. is an 18 carbon unit 2. Is produced by aldosterone synthase 3. Is formed from corticosterone in the zona glumerulosa of the adrenal cortex2, 3Which of the following compounds are 19 carbon units? 1. Progesterone 2. Cortisol 3. Dehydroepiandrosterone 4. Estriol 5. Testosterone3, 5Which of the following compounds are 21 carbon units? 1. Progesterone 2. Cortisol 3. Dehydroepiandrosterone 4. Estriol 5. Testosterone1, 2Which of the following compounds are 18 carbon units? 1. Progesterone 2. Cortisol 3. Dehydroepiandrosterone 4. Estriol 5. Testosterone4Cortisol synthesis 1. requires 3 hydroxylases 2. Is located in reticularis and fasciculata zones of adrenal cortex 3. 17a hydroxylation favors synthesis of cortisol1, 2, 3hich of the following compounds has (have) a hydroxyl group in position 17 alfa: 1. progesterone 2. 11-deoxycortisol 3 dehydroepiandrosterone 4.cortisol 5. estriol5Which of the following is (are) mitochondrial enzymes: 1. 18-hydroxylase 3. 17,20-lyase - 4. P450 side chain cleavage 5. Δ 5,4 isomerase - SER 5. 11B-hydroxylase1, 3, 5Presence of aromatase activity 1. Adipose 2. Ovary 3. Liver 4. Skin1, 2, 3, 4endoplasmatic reticulum enzymes: 1. 18-hydroxyase 2. C17,20-lyase 3. P450 side chain clevage 4. enzymes Delta 5,4-isomerase 5. 17alpha-hydroxylase2, 4, 5Choose true 1. Testosterone a prohormone, is substrate for biosynthesis of more active dihydrotestosteron 2. small amounts of plasma can be bound to albumin 3. ovarian aromatization of androgens requires P-450 Monooxygenase, O2, NADH1, 217-hydroxypregenolone: 1. can be the product of 3beta-hydrosterioid dehydrogenase 2. is substrate for 17,20 lyase 3. its oxidative fission at C17 position results in formation of dehydroepiandrosterone2, 3