Metabolic Integration Flashcards
What are the four things that Glucose-6-P can be converted to
- Glucose1-P for use in glycogen
- Glucose for release into the blood
- 6-phophogluconolactetone to generate NADPH by pentose phosphate pathway
- fructose-6-P, used in glycolytic pathway to produce pyruvate
What does creatine kinase do
catalyzes a reversible transfer reaction that generates ATP in muscle cells that is a source of energy for muscle contraction
What is resynthesized during the muscle recovery period
Phosphocreateine
The brain depends on ___ as its sole energy source
glucose
what is the function of astrocytes
in the brain transport glucose metabolites to surrounding neruons
what is hte main cite for PET imaging
Glucose in the brain
What is the main export in the liver
glucose and triaglycerols
triacylglycerols in the blood are hydrolyzed by what
LPL- lipoprotein lipase
T or F: amino acids, ketone and lactate are at high levels in the blood
F
what does the traicylglycerol cycle do
exchanges free fatty acids and triacylglycerols between adipose and liver cells
Where does the glycernogenic pathway function
apidoctes and hepatocyctes
Insulin and glucagon are ____ hormones produced in the ______ that control ______
peptide homrones produced in the pancreas and control glucose homeostasis
what secretes insulin in the pancreas
islets of Langerhans in beta cells
where is glucagon secreted
islets of langerhans in alpha cells
what do delta cells produce
somatostatin which controls the seceretory process
what do acinar cells synthesize
digestive enzymes
Insulin signaling in the brain activates signals that regulate ____
eating behaviour
what are the three key differences in insulin effects in lever vs muscle
- GLUT4 in skeletal, GLUT2 in pancreas
- skeletal muscles do not contain Glucose-6-p and fatty acid synthase so all glucose is used for metabolic fuel
- Mass of skeletal muscle 30x grater than liver, therefore insulin stimulation of glucose uptake in muscle is hte primary mechanism
activation of glucagon receptors in liver and adipose tissues incerases, what also increases to activate pKA
cAMP
pKA also phosphorylates what in liver cells
glycogen synthase and phosphoyrlase kinase
glucagon signaling in adipose tissue activates _____ hydrolysis
triacylglycerool
PPAR signaling medates long term control of ____ ______
lipid metabolism
PPAR alpha function
fatty acid oxidation, fasting response
PPAR y function
lipid synthesis, insulin sensitivity
PPAR d function
pentose phosphate pathway
ligand binding to the PPAR receptor leads to gene activation through ___ ____ ___
transcriptional initiation complex
conformational changes in PPAR-RXR heterodimer stimulate polyubiquination of _____ proteins tha recruit ______
corepressor, RNA polymerase
what are the four major changes in metabolic flux during starvation
1- increase release of fatty acids
2- increased gluconeogenesis in liver and kidney
3- increase ketogenesis in liver
4- protein degradation in skeletal muscle
What is the primary source of metabolic fuel during starvation
adopose and skeletal muscle
fatty acids regenerate _____ for citrate cycle and production of ketone bodies during starvation
actetyl-CoA
genetic defects in __ gene in mice leads to obesity
ob
injecting leptin leads to what
reduced food intake and body mass
leptin signalin pathways in first order POMC and NPY/AGRP neurons leads to decreased __________
fat storage
what is metabolic syndrome
a cluster of conditions that when put together can increase risk of heart attacks, diabetes, stroke etc
what are some symptoms of metabolic syndrome
insulin resistance, abdominal obesity, hypertension, hyperlipidemia
fatty acids lead to the activation of ____ _____ _
Protein kinase C
what is inhibits phophornostide-3 kinase in the insulin signaling pathway in obese individuals
Serine
What should normally be phosphorylated in insulin signaling pathway
Ter
Serum levels of free fatty acids in obese idividuals could promote ____ resistance in ____ cells
insulin, muscle
elevated levels of _____- __ leads to down regulation of gene expression and inhibition of insulin signaling
TNF-alpha
reduced levels of adipenectin results in decrease activation of ____ signaling in muscle cells
AMPK
what is hte most perscribed drug for treating type 2 diabetes
metformin
what does metformin do
increases AMP levels and activates AMPK signaling to improve glucose and lipid metabolism
AMPK plays a key role as a ____ ____
master regulator
what is an example in which AMPK would be activated
stress responses like low glucose
binding to AMPKy does what
activaetes the AMPK complex
T or F: AMPK complex enhances both transcription and translocation in GLUT4
T
What are thiazolidinediones
ligands for PPAR nuclear receptor proteins that when activating gene expression in adipose tissue it leads to increased insulin sensitivity
