Endocrine Glands

Question 0

After the coupling reactions are complete, what molecules will you find attached to thyroglobulin in the follicular lumen?

Answer 0

1. T3
2. T4
3. MIT
4. DIT

Question 1

What are the three actions of thyroid peroxidase?

Answer 1

1. Oxidation of I- to I2
2. Organification of I2 into thyroglobulin
3. Coupling reactions

Question 2

Why are T4 levels in the body higher than T3?

Answer 2

The process by which two DIT molecules combine is a faster reaction than the combination of one DIT and one MIT. Thus, you make 10 times more T4 than T3.

Question 3

Which enzymes are responsible for the hydrolysis of T4 and T3 from thyroglobulin?

Answer 3

Lysosomal proteases in the follicular cell