hormone action and signal transduction

Question 1

Which a,ong the following hormones, readily diffuse from ECF across the plasma membrane and go directly im the nucles
A. Glucocorticoids
B. Thyroid hormones
C. Retinoids
D.A and B
E. B and C

Answer 1

E.

Glucocorticoid diffuse across the plasma membrane and encounter their cognate receptor in the cyyoplasm of target cells

Question 2

In prokaryotic cells, cAMP binds to this specific protein that binds directly to DNA and influences gene expression

Answer 2

Catabolite regulatory protein

In eukaryotic cells-cAMP binds to protein kinase A

Question 3

Enzymes that terminate the increase cAMP concentrations by hydrolyzing cAMP to 5’-AMP

Answer 3

Phosphodiesterase

Inhibited by methyl xanthine derivatives

Question 4

Type I phosphothreonine phosphatase dephosporylates B subunit of phosporylase kinase while type II dephosporylase

Answer 4

a subunit

Question 5

A family of peptides produced in carfiac atrial tissues, cause natriuresis,diuresis,vasodilation and inhibition of aldostetone secretion

Answer 5

Atriopeptins

Question 6

Calcium-dependent regulatory protein homolohous to troponin C in structure and function

Answer 6

Calmodulin

Question 7

Catalyzes the hydrolysis of PIP to IP3 and diacylglycerol

Answer 7

Phospolipase C

Question 8

Hormone-receptor interaction promotes binding and activation of cytoplasmic protein tytosine kinases such as

Answer 8

Tyk-2, Jak1 or Jak2

Question 9

What heterohexameric structure is activated by extracellular stimuli such as proinflammatory cytokines, reactive oxygen species and mitogens

Answer 9

IkB kinase cimplex (IKK)

Question 10

Located at the carboxyl terminal half of the receptor that binds hormones and metabolites with selectivity

Answer 10

Ligand-binding domain (LBD)

Question 11

Provides flexibility between DBD and LBD to assume different DNA-binding conformations

Answer 11

hinge region

Question 12

Activated receptor moves from the cytoplasm to the nucleus and binds with high affinity to specific DNA sequence called

Answer 12

Hormone respomse element

Question 13

Receptors of group II hormones signal through guanine nucleotide-bound protein intermediates know as

Answer 13

G protein-coipled receptors

Question 14

The active C subunit catalyzes the transfer of the y phosphate of ATP to..

Answer 14

Serine or threonine residues

Question 15

What is the targeting proteins in PKA that serve as scaffolds, which localizes PKA near to substrate thereby focusing PKA activity toward physiological substrates

Answer 15

A kinase anchoring proteins (AKAPS)

Question 16

Effects of cAMP on gene transcriptionare mediated by the protein

Answer 16

Cyclic AMP response element binding protein (CREB)
(If phosporykated by PKA, CREB binds the coactivator CREB-bindibg protein CBP/p300 and as a result a much more potent transcription activator