Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
48 Cards in this Set
- Front
- Back
other neurotransmitters and hormones that have the same function as glucagon (3)
|
catecholamines (NE, Epi)
GH glucocorticoids (cortisol) *released in times of stress (e.g., exercise, illness)* |
|
delta cells
*location *synthesize (2) |
disperesed in islets of Langerhans' periphery
somatostatin gastrin |
|
F cells
*location *synthesize |
periphery of islets of Langerhans
pancreatic polypeptide (gastrointestinal hormone) |
|
stimulators of glucagon secretion (4)
|
hypoglycemia (bg <50 mg/dL)*most important*
increase in Arg and Ala (indicates protein degradation) sympathetic stimulation (e.g., exercise) stress (e.g., healing after surgery) |
|
T/F glucagon circulates in the blood bound to carrier proteins
|
False
|
|
inhibitors of glucagon secretion (3)
|
somatostatin *most important*
insulin hyperglycemia (bg >200 mg/dL) |
|
effects of glucagon on the liver (4)
|
glycogenolysis (glycogen --> glucose)
gluconeogenesis (amino acids --> glucose) lipolysis (TG's --> FA's --> glycerol --> glycerol-phosphate --> glucose) ketogenesis |
|
effects of glucagon on adipose tissue (2)
|
decreased glycolysis
increased lipolysis (release of FA's) |
|
levels of cAMP vs. glucagon and insulin
|
glucagon increases cAMP
insulin decreases cAMP |
|
in hepatocytes, glucagon _______ glycogenolysis and ______ glycogen synthesis by ______ cAMP
|
stimulates
inhibits increasing |
|
in hepatocytes, insulin _______ glycogenolysis and ______ glycogen synthesis by _________ cAMP
|
inhibits
stimulates decreasing |
|
cAMP controls the production of
|
fructose 2,6-bisphosphate
|
|
glycolysis:
cAMP catalyzes the phosphorylation of ______ thereby _____ it |
pyruvate kinsase
inactivating |
|
function of pyruvate kinase
|
converts PEP to pyruvate
|
|
_______ is the principal competitor of gluconeogenesis
|
lipogenesis
|
|
lipogenesis:
cAMP catalyzes the phosphorylation of ______ thereby ______ fatty acid synthesis (lipogenesis) |
acetyl CoA carboxylase (catalyzes the carboxylation of acetyl CoA to malonyl-CoA)
inhibiting |
|
long chain fatty acids must be linked to ______ in order to cross the mitochondrial membrane
|
carnitine
|
|
carnitine acyl transferase is inhibited by
|
malonyl-CoA
|
|
fatty acid oxidation & ketogenesis:
when fatty acid synthesis is inhibited (i.e., no ______) ________ is activated and fatty acid oxidation and ketogenesis occur |
malonyl-CoA
carnitine acyl transferase |
|
________ and ______ are formed from the condensation of 2 acetyl CoA molecules
|
acetoacetate
beta-hydroxybutyrate |
|
Fructose 2,6-bisphosphate activates ________and inhibits _________, therby favoring glycolysis
|
phosphofructo-kinase (PFK)
fructose-1,6-bisphosphatase |
|
fructose-2,6-bisphosphate is formed by the enzymes (2)
|
F-2,6-kinase
F-2,6-phosphatase |
|
glycolysis occurs when fructose-6-phosphate is _____ than fructose-2,6-bisphosphate
|
<<
|
|
glucagon stimulates a(n) ______ in cAMP, thus activating _____
|
increase
PKA |
|
PKA phosphorylates ______, which converts it to ______
|
fructose-2,6 kinase
fructose-2,6 phosphatase |
|
when fructose-2,6-bisphosphate is depleted ______ is blocked and _____ decreases
|
PFK
glycolysis |
|
gluconeogensis if favored when _______ activity increases and _______ is convereted to __________
|
fructose 1,6-bisphosphate phosphatase
fructose-1,6-bisphosphate fructose-6-phosphate |
|
after a meal stimulators of insulin secretion (4)
|
increased serum glucose
increased serum amino acids (Arg & Lys) increased serum free fatty acids increased serum ketone bodies (keto-acids) |
|
hormone stimulators of insulin secretion (7)
|
GIP
glucagon gastrin CCK secretin VIP Epi (beta receptor) *hormones that are elevated in the presence of food* |
|
neuronal stimulator of insulin secretion
|
PNS ("Rest & Digest")
|
|
"starvation" inhibitors of insulin secretion (3)
|
decreased serum glucose
decreased serum amino acids decreased free fatty acids |
|
hormone inhibitors of insulin secretion (2)
|
somatostatin
Epi (alpha receptor) |
|
increased entrance of glucose into the cell stimulates ________ leading to an increase in ______
|
glycolysis
ATP |
|
increased _____ inhibits an ATP-sensitive ______
|
ATP
K-channel |
|
Inhibition of an ATP-sensitiive K-channel causes membrane ______
|
depolarization
|
|
membrane depolarization activates a _________
|
voltage-gated Ca-channel
|
|
activation of a Ca-channel promotes Ca influx, which increases [Ca] and evokes ________
|
Ca-induced Ca release
|
|
elevated Ca leads to exocytosis and release of ______ into the bloodstream
|
insulin
|
|
Na-dependent secondary active glucose transporter located in the intestine and kidney
|
SGLT-1
|
|
facilitated diffusion glucose transporter located in the liver and pancreas
|
GLUT-2
|
|
glucose transporter which moves from the cytosol to plasma membrane in the presence of insulin
|
GLUT-4
|
|
major site of insulin-mediated glucose uptake
|
skeletal muscle (80%)
|
|
in the liver, insulin stimulates (5)
|
glucose uptake
glycogenesis glycolysis (supplies acetyl CoA for lipogenesis) fatty acid synthesis (lipogenesis) protein synthesis |
|
in the liver, insulin inhibits (6)
|
glycogenolysis
gluconeogenesis fat oxidation ketogenesis proteolysis urea cycle |
|
in skeletal muscle, insulin stimulates (5)
|
glucose uptake (GLUT-4)
glycogenesis glycolysis (provides acetyl CoA for lipogenesis) amino acid uptake protein synthesis |
|
in skeletal muscle, insulin inhibits (2)
|
glycogenolysis
proteolysis |
|
in adipose tissue, insulin stimulates (5)
|
glucose uptake (GLUT-4)
glycolysis (alpha-glycerol phosphate) production of alpha-glycerophosphate esterifcation of fats synthesis of lipoprotein lipase |
|
in adipose tissue, insulin inhibits (1)
|
lipolysis
|