Cell-Cell Communication 6

Question 1

What are some examples of small, lipophilic molecules that can diffuse directly across the plasma membrane of target cells?

Answer 1

Steroid hormones, thyroid hormones, retinoid and vitamin D.

Question 2

After the intracellular receptor-hormone complex binds in the cytosol, where does it go next?

Answer 2

To the nucleus for transcription.

Question 3

T/F: Intracellular receptors can be both receptors and effectors of the signal.

Answer 3

True.

Question 4

What are PPARs?

Answer 4

Bind to intracellular lipid metabolites and regulate the transcription of genes involved in lipid metabolism and fat-cell differentiation.

Question 5

What do PPAR alpha agonists do?

Answer 5

Decrease blood lipids.

Question 6

What do PPAR gamma agonists do?

Answer 6

Decrease lipids and inflammation, treat type 2 diabetes.

Question 7

T/F: Some receptors are bound to DNA in the nucleus even in the absence of ligand.

Answer 7

True.

Question 8

What do inactive receptors bind to?

Answer 8

Inhibitory protein complexes.

Question 9

What molecule can repress the activation or repression of genes?

Answer 9

Glucocorticoids

Question 10

What are coated pits?

Answer 10

Specialized regions of the PM composed of pits coated with a bristle covering, made of the protein, clathrin.

Question 11

What is one molecule that uses receptor mediated endocystosis?

Answer 11

Cholesterol