Biochem

Question 1

cholesterol is used to make what 3 important biological substances?

Answer 1

steroids, bile acids, and vitamin D

Question 2

what is the StAR protein? What is its location in the cell, and why is this important to its function?

Answer 2

Steroidogenic acute regulatory protein. It regulates steroid biosynthesis as a gate keeper to the mitochondria. It moves cholesterol from the outer to inner membrane. This is important b/c descales is kept in the inner membrane ready to catalyze the first step of steroid biosynthesis

Question 3

Where is desmolase located in a theca cell?

Answer 3

Within the inner mitochondrial membrane ready to catalyze cholesterol to pregnenolone

Question 4

how do cytochrome p450 enzymes work?

Answer 4

Facilitate the oxidation of compounds (like cholesterol, or drugs) which increases their solubility.

Question 5

which of the following is NOT a CYP enzyme?

desmolase
17-alpha-hydroxylase
3-beta-hydroxysteroid dehydrogenase
17-20 lyase

Answer 5

3-beta

Question 6

Which specific estrogen is created when female granulosa cells convert androstenedione? What male hormone would be created if 17-beta HSD was used rather than aromatase?

Answer 6

estrone (ketone) E1

testosterone

Question 7

Testosterone is covered to DHT via what enzyme?

Answer 7

5-alpha reductase