Thyroid Agents - Khan - Exam 1

Reorder the following steps of biosynthesis and release of the thyroid hormones

• Uptake of iodine by the thyroid

• Formation of t4 and t3 from iodotyrosine

• Secretion of thyroid hormones

• T4 to t3 conversion in peripheral tissue

• Oxidation and iodination

The major circulatory form of thyroid hormone is

• T4

• T3

The active form of thyroid hormone is

• T4

• T3

Triiodothyronine is formed from

• Two DIT

• One MIT and one DIT

• Two MIT

Thyroxine is formed from

• Two DIT

• One MIT and one DIT

• Two MIT

The coupling of DIT/MI is catalyzed by

• Thyroidal peroxidase

• 5' deiodinase

• PKA

• Thyroglobulin

T4 is converted to t3 by which enzyme

• Thyroidal peroxidase

• 5' deiodinase

• PKA

• Thyroglobulin

Where does thyroid hormone bind?

• Nuclear receptor

• Cytosolic receptor

• Membrane receptor

Which of the following is the boxed warning for Levothyroxine

• Must not be used to treat obesity

• Cough

• Can cause severe liver toxicity

• Contraindicated in pregnancy

Which of the following is the boxed warning for Propylthiouracil

• Must not be used to treat obesity

• Cough

• Can cause severe liver toxicity

• Contraindicated in pregnancy