Lecture 2: Classification Of Hormones

Question 1

Which hormone type requires a blood transporter

Answer 1

Lipophilic

Question 2

What hormone type can’t cross the cell membrane?

Answer 2

Hydrophilic

Question 3

What are the transporters of steroids?

Answer 3

Cortisol and aldosterone

Question 4

What does ACTH bind to?

Answer 4

Melanocortin-2 receptors in the plasma membrane

Question 5

The ACTH binding to the receptors causes…?

Answer 5

Increase in intracellular cAMP production

Question 6

Enzymes of steroid bio synthesis are distributed in…?

Answer 6

Mitochondria and smooth endoplasmic reticulum

Question 7

What is the rate limiting step?

Answer 7

Cholesterol changing to pregnenolone

Question 8

What is the enzyme acting on the rate limiting step encoded by?

Answer 8

CYP 11A1

Question 9

Where is CYP 11A1 located?

Answer 9

Inner membrane of mitochondrial membrane of the adrenal cells

Question 10

How does ACTH affect steroid synthesis?

Answer 10

It increases the rate limiting step

Question 11

How does ACTH increase the rate limiting step?

Answer 11

Via increasing the availability of cholesterol within the cell

Question 12

How does cholesterol become more available in the cell via ACTH?

Answer 12

It’s uptake increases via the HDL and LDL receptors