Turco 2 Flashcards
Complete pyruvate kinase defect
kills you
Diabetes glucose curve
Higher peak and takes longer to come back down…diabetic will get hungry before it ever comes back down all the way and will eat more…extra glucose in the blood for extended periods of time
Pathology of diabetes from
Glucose concentration in the blood
Insulin effect of GLUT4
GLUT 4 premade and sits in vesicles…insulin will cause vesicles to open and move to the membrane…more GLUT4 on surface means higher Vmax so more glucose entering
Type 1 vs type 2
1 - insulin scretion problem
2 - receptor problem
Obesity receptor effect
Leads to decreased eceptors
INsulin dependent tissues in body
Muscle (GLUT4)
Adipose tissue (GLUT4)
Liver (different effects)
Insulin effect on muscle of adipose
Increase uptake of glucose
IMpact of insulin on liver
Tells the liver to trap it using glucokinase…run glycolysis and create fatty acids ,etc.
Hemoglobin effect of hyperglycemia
Aldehyde from glucose reacts with amine group of hemoglobin to create A1C (glycosylated hemoglobin)
Values of A1C
6% or less is normal
7% or over is diabetic
6-7 is pre
Glucose effect on kidney
Binds transporters and renders them non-functional
Glucose effect on collage
Binds collagen and extends 1/2 life…means that capillary beds are restricted…why amputations occur
Glucose effect of brain
Hyperosmolar edema (draws water)
Glucose reaction with hemoglobin is
Non-enzymatic, irreversible
Formation of F2,6P
Formed from F6P by PFK2 using ATP
Location of F2,6P
Liver ONLY
WHere does F6P come from?
Glycolysis
PFK2 regulation
Positively by insulin
Negatively by glucagon
PFK2/PFK1 relationship
If one is active, the other will be active…F2,6P increases activity of PFK1 by overriding any other inhibitors
F2,6P other regulation
Turns off F1,6bisphosphatase of gluconeogenesis
All cells except liver after high carb
Glucose becomes pyruvate through glycolysis
Increase ATP, decreased PFK1, Decreased glycolysis
IN liver after high carb meal
Glucose becomes pyruvate
INsulin leads to increase in PFK2, increased in F2,6P, increase in PFK1, and increase in glycolysis
Leads to production of fatty acid synthesis
IN short, F2,6P activates what and inhibits what?
Activates glycolysis and inhibitsa gluconeogenesis
Without F2,6P
You would not be able to overcome inhibition of PFK1 and would never make fatty acids
Effects of diabtetes on hepatic glycolysis
No PFK2 means decrease in PFK1 means decreased glycolysis
Increased F6P means increased G6P means decreased hexokinase activity and can’t keep glucose in the liver
No glucokinase activity because no insulin so no glucose trapping
NAD+
Only small amounts
Converted to NADH in catabolic reactions and makes ATP
NADP
Converted to NADPH and NADPH used for anabolic reactions
Where does NAD come from?
Niacin
NAD and NADP relationship with enzymes
Noncovalently bound to enzymes
Cholera toxin mech
ADP ribosylation uyses NAD as substrate to create ADP ribose
NADPH particularly importasnt in
NADPH oxidase of inflammation
Are NAD and NADP interchangeable?
No
Aerobic fate of pyruvate
2 pyruvate converted to 2 acetyl-CoA with loss of 2 CO2…2 acetyl CoA converted to 4CO2 and 4H2O and create a bunch of ATP
Anaerboci fate of pyruvate
Create lactate (in vigourously contracting muscles, erythroicytes)
Other fate of pyruvate
Converted to alanine
Aerobic glycolysis equation
Glc + 2ADP+2NAD —-> 2 pyr + 2ATP + 2 NADH
NADH—-> more ATP via oxidative phosphorylation
Anaerboic glycolysis
Blc —-> 2 lactate and 2 ATP (substrate level phosphorylation)
Pyruvate conversion to lactate reactions
Lactate dehydrogenase using NADH
In muscle and liver cytoiplasm
In conditions of high demand
INcreased ATP need, increased rate of oxidative catabolic reactions and increased NADH generated
Point of exercise
Trying to condition lungs ot bring in more O2 and make more ATP
Smokes
Will produce more lactic acid because less oxygen uptake
What is the point of the lactic acid pathway?
Recycles NAD
How long does it take to recover from lactic acid production?
About an hour
Cori cycle
Glycogen converted to glucose…glucose undergoes glycolysis to pyruvate…pyruvate goes to lactate…lactate moved to blood to liver…in liver, lactate to pyruvate to glucopse via gluconeogenesis…glucose moved bacxk to muslce through blood
Alanine cycle
Similar to lactate cycle except no pH effect on the blood
Why does body prefer Cori cycle to alanine cycle?
LDH regenerates the NAD for glycolysis
