Signal Transduction Flashcards
what are intracellular signal?
signal that come from WITHIN the cell
what are intercellular signals?
responses to extracellular signals to coordinate metabolic activities
what are the 3 characteristics of G-protein coupled receptors (GPCR)?
- extracellular ligand binding domain
- 7 transmembrane spanning domains
- intercellular G-protein activation domain
does G-protein stimulate or inhibit adenylyl cyclase?
either depending on the receptor (GPCR)
What are the three things that protein kinase A catalytic subunits can phosphorylate?
DNA binding proteins
ion channels
enzymes
what are the 2 enzymes that can stop the signal transduction pathway?
protein phosphatases
cAMP phosphodiesterase
Calcium binds to ________ in the liver to activate enzymes and initiate metabolism?
Calmodulin
what factors negatively affect insulin secretion?
increased epinephrine
decreased dietary fuels
what causes the secretion of epinephrine?
stress
trauma
extreme exercise
what factors positively affect insulin?
amino acids
glucose
What is the enzyme that insulin activates?
Tyrosine kinase
What does tyrosine kinase phosphorylate?
IRS
Glucagon secretion is stimulated by?
Increasing epinephrine levels
Increasing amino acid levels
Glucagon is inhibited by?
Increasing glucose and insulin levels
What is the blood glucose level of hypoglycemia?
< or = 70 mg/dl
What are the 3 types of hypoglycemia?
Postprandial
Insulin induced
Fasting
