Biochem: Hormone Action

Question 1

What are the 3 components of the steroid hormone receptors in cells?

Answer 1

1. Amino Ligand-Independent Transactivation domain:
2. DNA-binding domain: binds onto DNA or transcription factors to initiate transcription
3. Ligand-binding domain: binds either heat shock proteins or a steroid hormone

Question 2

What are heat shock proteins (HSP)?

Answer 2

A protein that protects an intracellular receptor from being degraded when it is not active as well as maintaining tertiary structure and prevents aggregation of the receptor with other proteins.

Question 3

Why are steroid hormones synthesized as needed?

Answer 3

They cannot be stored in cytoplasmic vesicles like peptide hormones due to hydrophobicity of their structures.

Question 4

Which hormones come from Tyrosine?

Answer 4

Catecholamines: DA, NE, Epi

Question 5

Which hormones come from Tryptophan?

Answer 5

Melatonin, Serotonin

Question 6

Which hormone uses Tyrosine kinase with a Phosphoinotisol-3 (PI-3) kinase pathway?

Answer 6

Insulin

Question 7

Which two hormones use the Janis Kinase or JAK/STAT pathway?

Answer 7

1. Growth Hormone

2. Prolactin

Question 8

What messenger pathway does Epinephrine use?

Answer 8

Gs or G alpha Stimulatory pathway

-involves adenylyl cyclase, cAMP, PKA, and CREB