Biochemistry-Hormones Of Gonads

Question 1

Where does testosterone synthesis takes place?

Answer 1

Leydig cells

Question 2

the rate limiting step in testosterone synthesis uses what transport protein?

Answer 2

Steroidogenic acute regulatory protein (StAR)

Question 3

What is the predominant hormone during fetal development?

Answer 3

Testosterone

Question 4

What is the predominant hormone after birth and before puberty?

Answer 4

Androsterone

Question 5

What is the normal rate secretion of testosterone in adult male?

Answer 5

5mg/ day

Question 6

In transport of gonadal hormones, the sex hormone binding globulin has higher affinity to:

Testosterone or estrogen

Answer 6

Testosterone

Question 7

Sex hormone binding globulins are produced by the liver and increased by EXCEPT:
A. Estrogen
B. Liver disease
C. Hyperthyroidism
D. Hypothyroidism

Answer 7

D

Question 8

What is the primary function of SHGB

Answer 8

Restrict free concentration of testosterone in the serum

Question 9

What is the active form of testosterone in seminal vesicle and prostate?

Answer 9

DHT

Question 10

What catalyzes the conversion of testosterone to DHT?

Answer 10

5a-reductase

Question 11

DHT predominantly expressed in the liver

Answer 11

Type I

Question 12

Testosterone synthesis is regulated by

Answer 12

Negative feedback

Question 13

LH stimulates testosterone production in _____________by enhancing rate of cholesterol side-chain cleavage

Answer 13

Leydig cells

Question 14

FSH binds to sertoli cells and promotes synthesis of ___________ to transport testosterone in very high conc to site of spermatogenesis

Answer 14

ABP

Question 15

Hormone produced by sertoli cells that inhibit FSH synthesis and secretion

Answer 15

Inhibin

Question 16

Which has higher affinity to receptor? DHT or Testosterone?

Answer 16

DHT

Question 17

Esterification of ______ produce more lipid soluble anabolic steroids

Answer 17

17b- hydroxyl group

Testosterone propionate
T cypionate
Enanthate

Question 18

Anabolic steroid that slows catabolism by the liver

Answer 18

Alkylation at 17a position

Question 19

Finasteride and Dutasteride are used in treatment of benign prostatic hyperthrophy by inhibiting

Answer 19

5a- reductase

Question 20

Hypogonadism due to defective gonadothropin secretion

Answer 20

Secondary

Question 21

Testicular feminization syndrome with feminized external genetalia is due to defect in

Answer 21

Testosterone receptor

Question 22

A disease due to increased DHT or T particularly in older males which leads to difficulty in urination

Answer 22

Benign prostatic hypertrophy

Question 23

The primary estrogen from the ovaries

Answer 23

Estradiol E2

Question 24

An estrogen formed from androstenedione

Answer 24

Estrone E1

Question 25

Produced during preganacy from placenta

Answer 25

Estriol

Question 26

Biosynthesis of female sex hormones is thru

Answer 26

Aromatization of androgens

Question 27

Cells that convert androstenedione and T to estrone and estradiol

Answer 27

Granulosa cells

Question 28

Produces progesterone and some estradiol

Answer 28

Corpus luteum

Question 29

What are the two functions of gonads?

Answer 29

1. Produce germ cells

2. Produce sex hormones