RBCenergy Flashcards
what does a G6PD glucose 6 phaspate dehydrogenase defeiceincy lead to
a hemolytic high bilirubin count
what is extravascular hemolysis
No RBC lysis in vascular when they are old and inelastic the RBC are trapped in the spleen and phagocytosed by macrophages.
what is hereditary spherocytosis
spectrin mutation leads to rounded short lived cells most common in the plasma membrane defect of the cytoskeleton.
what is intravascular hemolysis
when the mechanical stress leads to cells breaking playing the bongos for too long. Release of Hemoglobin from RBC and leads to a Hemoglobinuria
what is extravascular hemolysis
removal of old RBC by spleen releasese bilirubin and can cause jaundice.
what are the four purposes of RBC metabolism
keeping iron in the Fe2+ state for NADH, maintaining K+/Ca2+ gradients for ATP, keeping the protein SH groups reduced NADPH, and maintaining cell shape ATP.
what happens if RBC metabolism fails
cells fill will Ca2+ cells release K+ and they lose the biconcave shape.
what are the two ways that RBC deal with glucose and fatty acids
they use glycoloysis and the PPP pathway and they do not use fatty acids only glucose.
what does the PPP make
NADPH to keep the SH groups oxidized
how is glycoslysis different in the RBC
it does not need insulin to uptake the glucose and doesn’t respond to glucagon as well.
what happends with the extra NADH that is made in glycoslysis in an RBC
makes pyruvate into lactate
what are the regulatory steps in the glycolysis in RBC
hexokinase and phosphofructokinase 1 not responseive to insulin and is responsive to PH
what is the energy clutch
through the 2,3 bisphosphoglycerate it can still make the NADH without making the ATP so it can skip the energy production if needed.
how does PH effect glycolysis
acidic PH inhibits glycolysis leading to less lactate protection inhibitw PFK 1
what happens to 2,3 BPG synthesis at low PH and how does this effect O2 loading and unloading
Reduces 2,3 BPG and this improves oxygen saturation, this will improve the affinity at the lung leading to better O2 loading, but the boar effect will lead to an increase in unloading at the target tissue that is very acidic.
what happens with the pentos phosphate during the PPP in a RBC
through a sercies of transaldolase and transketolase reactions they are reintroduced into the glycolysis pathway and then excreted.
what is glutathione and what does it do
is an antioxidant protects the RBC from the sulfer groups and detoxes hydrogen peroxide H2O2 after its made from O2- by superoxide dismutase.
what does glutathine need to convert h2o2 to 2 h20
NADPH is needed from the PPP
what do enzymatic problems cause
nonspherocytic anemia,
what does a G6PD deficiency cause
hemolytic anemia for lack of NADPH needed for glutathion
what does a pyruvate kinase deficiency cause
hemolytic anemia for lack of NADH and ATP
tell me about a g6PD deficiency
x linked prevalent in Africa and Mediterranean, hemolytic crisis triggered by infection h2o2 producing drugs like antimalarial and flava beans causes splenomegaly and jaundice and RBC with a bite out of them by macrophages.
tell me about Pyruvate kinase deficiency
hereditary non spherocytic hemolytic anemia, crisis not triggered by ROS leads to splenomegaly and jaundice. Black spots in the RBC
what does fluoride/potassium oxalate do to RBC
stops glycolysis with fouride and exalate is an anticoagulatn used to measure glucose or lactate
tell me about the metabolism of cancer cells
tumor cells get energy from glycolysis making lots of lactate and do it under hypoxic condition so they express hypoxia inducible factor to support anaerobic metabolism
how do you treat someone with RBC cytoskeletal defects
most common is the ankyrin mutation and it can be treated by removal of the spleen.
