Biochemistry-Steroids Flashcards Preview

NPLEX I > Biochemistry-Steroids > Flashcards

Flashcards in Biochemistry-Steroids Deck (24)
1

Where does cholesterol synthesis take place?

liver and intestines

2

Where in the cell does cholesterol synthesis take place?

cytoplasm

3

What is the precursor for cholesterol synthesis?

Acetyl-CoA

4

What pathway is the greatest producer of Acetyl-CoA?

beta-oxidation

5

What is the regulatory enzyme of cholesterol synthesis?

HMG-CoA reductase

6

What hormone promotes the action of HMG-CoA reductase?

Insulin

7

What are 2 significant intermediates in cholesterol synthesis?

HMG-CoS, mevalonate, squalene, desmuterol

8

What is the function of cholesterol?

membran fluidity, precursor to all steroid hormones

9

What type of fatty acid increases cholesterol? What type of fatty acid decreases cholesterol?

Increases: saturated fats
Decreases: unsaturated fats

10

What other metabolite is formed from mevalonate?

CoQ10

11

What 2 substances act as conjugating agents to convert bile acids into bile salts?

Taurine, Glycine

12

What enzyme is involved in bile acid production?

7-alpha hydroxylase

13

What vitamin is needed for the activity of 7-alpha hydroxylase?

Vitamin C

14

What are the 2 primary bile acids?

Cholyl-CoA
Chenodeoxychoyl-CoA

15

What the 2 secondary bile acids?

Deoxycholic acid
lithocholic acid

16

Where are bile acids formed?

Liver and intestines

17

Where are bile acids stored?

gallbladder

18

Where does bile acid reabsorption take place?

ileum

19

What are 2 functions of bile acids?

Fat emulsification
Cholesterol excretion

20

Testosterone is produced in which tissue?

Adrenal cortex

21

Estrone and estradiol are produced in which tissue?

Ovaries and a small amount in the adrenal cortex

22

DHEA, progesterone, cortisol and aldosterone are produced in which tissue?

adrenal cortex

23

What is the precursor for steroid hormones?

cholesterol

24

What vitamin is needed for steroid hormone production?

Vitamin C