Cellular Homeostasis Flashcards
Where are glut 1 receptos found?
everywhere but mainly in the brain and rbc
where are glut 2 receptors found?
liver and pancrease, this is how beta cells know how to secrete insulin
Where are glut 3 receptors found?
neurons
where are glut 4 receptors founf?
skeletal muscle tissue, heart, and adipose tissue
Which glut R is regulated by insulin?
glut 4
How many ATP are made from 1 molecule of glucose
34-36
what is the ultimate product of anaerobic glycolysis?
2 lactate and 2 NAD+
3 suppliers of glucose?
diet
glycogenolysis
gluconeogenesis
Fanconi Bickel Syndrome is caused by
inherited deficiency of glut 2 receptors in the liver, pancreas, and proximal renal tubule- so your body doesnt know to secrete insulin and stimulate the GLUT 4 in muscle and fat so the clearing of excess blood glucose
S/S of Fanconi Bickel Syndrome
hepatomegaly, stunted growth, hyperglycemia after a mean and hypoglycemia during fasting
Why does Fanconi Bickel Syndrome cause hepatomegaly?
because glycogen stored in the liver cannot get out
Rx for Fanconi Bickel?
ingestion of small meals throughout the day and supplementation of vitamin D (proximal tubular nephropathy prevents uptake and can lead to rickets)
Is the Glut 2 transporter uni or bi directional?
bidirectional depending on the concentration
High—— low—— system
capacity, affinity
How does gluoce sensing by Glut 2 work?
glucose is taken into the cell and ATP is made from it. Rishe in ATP closes K+ channels causing depolarization which opens voltage gated Ca++ channels. Influx of Ca++ triggers release of already synthesized insulin molecules and the synthesis of more insulin in a slow release pathway
What is the glucose tolerance test?
involves a patient ingesting a known amount of glucose followed by 8-12h. fasting period
What is normal fasting glucose?
less than 6
After 2 hours of eating normal gluc? diabetes?
11.1
How is PEPCK regulated?
PEPCK takes pyruvate to OAA in the synthesis of glucose. Its synthesis is regulated by TF’s thyroxine and cortisol
what do chaperones and enzymes do for newly made protein?
help it to fold properly
What do Hsp70 and Hsp90 do?
chaperones that aid in proper folding of proteins
What does the TOM complex do?
recognized the signal recognition sequence and binds precursor protein. It then allows protein into the intermembrane space of the mitochondria
What does the TIM complex do?
TIM live in the inner membrane of mitochondria and allows protein tagged with a special signal to enter into the matrix for folding and modification
4 types of PTM
Acetylation, glycation/glycosylation, phosphorylation, and ubiquitination
2 methods to degrade proteins
lysosome (mainly used for intermembrane proteins and endocytosed agents)
proteasomes (mainly stuff in house)
How are extracellular protein degraded?
proteoytic enzymes often secreted in their inactive form (zymogens)
What is autophagy?
catabolism where dysfunctionl cellular components are degraded and other cellular components are recycled
How are cells usually degraded?
autophagy and fusion with lysosome
Which 4 things happen in mitochondria?
beta oxidation of fatty acids, TCA, urea cycle, and ctorage of Ca++
Fusion of mitochondria happens when
a sick mitochondria fuses with a well mitochondria in order to mitigate healing
fission of mitochondria happens when
we need to create new mitochondria, to remoe damaged mitochondria, and to facilitate apoptosis
