Messengers + receptors

Question 1

where do hydrophilic and hydrophobic ligands bind

Answer 1

hydrophilic- extracellular receptors

hydrophobic- intracellular receptors

Question 2

What do G protein linked receipts contain

Answer 2

7 transmembrane a helices
extracellular loops to bing specific messengers
Intracellular loops that interact w specific g proteins

Question 3

When are G proteins “on”, “off”

Answer 3

GTP bound= on

GDP bound= off

Question 4

Two classes of G proteins

Answer 4

large hetêrotrimeriç (Gaby)

small monomeric

Question 5

What is cAMP, how is it formed what is the target protein

Answer 5

• second messenger for some g proteins
• formed from ATP
• Target is protein kinase A (regulates PKA)

Question 6

what increases cytosolic Ca+

Answer 6

Opening of calcium channels in PM

calcium release from ER

Question 7

what decreases cytosolic Ca+

Answer 7

calcium ATPases (transport ca out)
mitochondria take up Ca

Question 8

Two categories of protein kinase associated receptors

Answer 8

1. tyrosine kinases, that phosphorylate a try residue

2. serine/threonine kinases, that phosphorylate a Sea or The residue

Question 9

Steps of RTK single transduction cascade

Answer 9

ligand binding
dimerization of RTKs
autophosphorylation
phosphorylated RTK recruits pro. with SH2 domain

Question 10

4 categories of endocrine hormones

Answer 10

amino acid derivates (epinephrine)
peptides (vasopressin)
Proteins (insulin)
Lipid like hormones (test)