Carbs IV Flashcards
where does glycogen synthesis occur
liver and muscle cells
what are the steps of activation of glucose
- glucose phosphorylation by hexokinase to glucose 6 phophate
- G 6P —> glucose 1 phophate by phosphoglucomutase
- G1P —> UDP glucose ia UDP glucose pyrophorylase
in general what is happening during glycogen synthesis
adding activated glucose in alpha 1.4 linkages and later branches the chains with alpha 1.6 bodns
what becomes active when blood glucose levels are low
glycogen phosphoylase
what is the regulated step of glycoen syntehsis
glucose to glucose 6 phophase
glycogen synthase
what is hexokinase and glucokinse stimulated by
insuline
what is hexolinase inhibtied by
g6p
what is glucokinas einhibted by
hexxokinase isozyme in liver NOT g6p
what is glycogen synthase inhibted by
glucagon, epinephrine
what is glycogen synthase stimulated by
insuline
what are the regulated steps in glycogen degration
glucogen phophorylase
glucose 6 phosphatse
what inhibts glucogen phophorylase
inusline
what is glycogen phosphorylase sitmualted by
glucagon, epinephrine
waht is glucose 6 phosphatase inhbited by
insulin
what is glucsoe 6 phosphatase sitmualted by
glucagon, epinephrine
how does insulin affect blood sugar conc
lowers
how does glucagon affect blood sugar conc
elecates
what is livers role in glucose
a resevoir for glucose
why can muscles not release glucose
they are lacking glucose 6 phosphase
how does epinephrine affect muscles
causes them to break down glycogen but in addition activate glycolysis to generate ATP
what does phosphorylation favor
glycogen degradation
what happens when glucagon or epinephrine bind to receptors on cell surface
activates adenylate cyclase
what happens when adenylate cyclase is activated
increase in cAMP
what happens when you have elevated cAMP
stimulate protein kinase A
what does protein kinase A do
activate phosphorylase kinase
what does phosphorylase kinase do
phosphorylates glycogen phosphorylase, starts degradation o glycogen
what is the other target of active protein kinase A
glycogen synthase
what is the only organ that expresses glucose 6 phosphatase
liver
affect of insuline on liver
activate glycoen synthase
ianctivate glycogen phosphorylase
stimulate glycolysis and ATP generation
affect of glucagon on liver
inactivate glycogen synthase
activate glycogen phosphorylase
activate glucose 6 phosphatase
activate gluconeogensis
affect of epinephrine on liver
inactivate glycogen synthase
activate glycogen phosphorlase
activate glucose 6 phosphatase
affect of insulin on muscle
stimulate glucose uptake
stimulate glycolysis and ATP generation
increases muscle glycogen and creatine phosphate levels
affect of glucaon on muscle
no affect
affect of epinephrine on muscle
inactivate glycogen sythase
activate glycogen phosphorlase
sitmlate glycolysis
type 1/van gierke results from defec tin what
glucose 6 phosphatase
symptom of type 1/von gierke
hypoglycemia, increased liver glycogen stores
type ii or pompe is caused by
deficienly of acid maltase
symptom of type ii/pompe
lysosome fill with glycogen, cardiac or respiratory failure causes death
type iii/cori disease is cauded by what
defect in glycogen debranching enzyme
type V/Mcardle is caused by what
defect in muscle glycogen phosphorylase
symptom of type V/McArdle
exercise intolerance
what are the 2 pathways for alcohol metabolism
2 dehydrogenase reactions
MEOS pathway
how does ethanol metabolism affect NAD and NADH
reduces amount of NAD and increases amount of ANDH in cytoplasm
what happens when NADH conc is high
pyruvate adn OAA disppear, get converted into lactate and malate
what happens to the ecxess lactate
accumualtes in blood, metabolic acidosis,
what does NADH reduce that capacity for
gluconeogensis
what does NADH block
CAC
