Signal Transduction Flashcards
Insulin is the signal that tells our tissues we ________ glucose
need to store
glucagon and epinephrine are signals that tells us _______
to release more glucose
chemical messengers that bind to cell surface receptors generate a __________ inside the cell
2nd messanger
changes in 2nd messenger levels lead to changes in _______ inside the cell
protein activity
what are the three classes of cell surface receptors?
ion channels, tyrosine kinase receptors, G protein coupled receptors
Cytosolic Ca2+, membrane potential, and insulin release are _______ receptors
ion channel
insulin, and epidermal growth factor (EGF) are _______ receptors
tyrosine kinase
epinephrine, glucagon and cAMP are ________ receptors
G-protein coupled
cytosolic Ca2+ is a key ____ messenger
2nd
Ca2+ channels allow Ca2+ ions to diffuse through the _________, down its electrochemical gradient
cell membrane
Ca2+ channels directly regulate levels of ________
ca2+ in the cytosol
- cytosolic Ca2+ is ____ in a cytosol at rest, and the plasma membrane potential (Vm) is _______ inside (polarized)
LOW, negative
- a more______ membrane potential inside (depolarized) increases cell activity
positive
- depolarization of the membrane potential causes voltage gated Ca2+ channels to _______
open
- when Ca2+ channels in the plasma membrane are open, Ca2+ flows from outside the cell into the _____
cytosol
potassium channels indirectly regulate _______ by changing the membrane potential, Vm
cytosolic Ca2+
When the potassium channels are open, membrane potential is _____, causing Ca channel to ______ and less Ca2+ enters cytosol
polarized, close
When the potassium channels are closed, membrane potential is _____, causing Ca channel to ______ and more Ca2+ enters cytosol
depolarized, open
ATP gated potassium channels couple high blood glucose to _____ release in pancreatic beta cells
insulin
Katp channels are open when ATP in the cell is _______ (polarized, less Ca2+ enters the cytosol)
LOW
Katp channels are closed when ATP in the cell is______ (depolarized, more Ca2+ enters cytosol)
HIGH
ion channels couple glucose catabolism and ATP to insulin release from _____
pancreatic beta cells
G proteins with GTP bound are _______ and interact with target proteins
active
G proteins are also _____ (GTPase), that hydrolyze GTP to GDP
enzymes
G proteins with GDP bound are _______
inactive
nucleotide exchange factor helps release ____
GDP
GTPase makes the G protein ______
inactive
The small GTPase, Ras, regulates cell growth through _______ and ______ protein kinases
serine, threonine
heterotrimeric G proteins (alpha, beta, gamma) couple G-protein coupled receptors to _________systems
2nd messenger
the alpha part of the g protein is a GTPase where its inactive with _______ and active with _____
GDP, GTP
When the alpha g protein is active it alters the activities of _______ and _____
enzymes, ion channels
Adenylyl cyclase (AC) converts ATP into _______
cAMP
cAMP is a ______ messenger
2nd
G-alpha-s-GTP activates
Adenylyl cyclase (AC)
G-alpha-i-GTP inhibites
G-alpha-s-GTP
G-alpha-s ______ adenylate cyclase, increases cAMP, protein kinase A is _______
stimulates, activated
G-alpha-i ______ adenylate cyclase, decreases cAMP, protein kinase A is _______
inhibits, less active
G-alpha-q ________ phospholipase c, ______ IP3, DAG, and Ca2+, protein kinase C is ______
stimulates, increases, activated
the glucagon receptor interacts with G-alpha-s which, when _______, stimulates adenylate cyclase and an _______ in cAMP
active, increase
epinephrine is the _______ hormone
acute stress
insulin signaling pathways regulate _______ and _______
fuel metabolism, cell growth
the insulin signaling pathway stimulates cell growth through _______
MAP kinase
Insulin signaling pathways fuel metabolism through 1. increasing ________trafficking to the cell surface, 2. ________ of glycogen, lipid and protein, and 3. ________ glucose release from the liver
GLUT4 , increase synthesis, suppress
growth factor receptor tyrosine kinases activate ______ G-proteins
Ras
Epidermal derived growth factor (EGFR) and Ras are associated with ______
oral cancer
