Acid Base Homeostasis Flashcards
How is H+ produced by our metabolism
anaerobic glycolysis - glucose -> 2 lactate plus 2 H+
metabolism of triglycerides (incomplete) - in adipose tissue triglyceride from fatty acids and H+, in the liver free fatty acids produces ketones and H+
neutral amino acid metabolism
why is having high H+ in the blood bad
they bind to proteins and cause conformational change
what are the main buffers in the body
(H+ acceptors) bicarbonate phosphate ammonia Hb proteins
what is the difference in a patient being academic vs alkalemic
acid - if pH is less than 7.35
alk - if pH is greater than 7.45
what is ka vs pKa
ka - acid dissociation constant
pKa - negative log Ka
what does a low pKa mean
stronger the acid
what does blood pH depend on in terms of the HH equation
the ratio between CO2 and HCO3-
how does bicarbonate HCO3 act as a buffer
H+ acceptor
cannot buffer CO2
how does phosphate act as a buffer
between mono hydrogen phosphate and dihydrogen
important buffer in urine!
how does ammonia act as a buffer
ammonia and ammonium ions buffer pair
NH3 important buffer in urine
how does haemoglobin act as a buffer
CO2 in plasma diffuses into the RBC - converted to H2CO3 with water and it then dissociates to please HCO3 into the plasma
what happens to RBC in the decoy state
Hb reduced to HHB
how do proteins act as buffers
small amount go acceptation and donation of H + due to amino acid composition
eg albumin - net negative charge, or bone proteins
what are 4 sites where acid base metabolism occurs in the body
lungs
kidneys
liver
GIT
what AB occurs in the lungs
excretes O2
in healthy people rate of elimination = production so blood pCO2 remains constant
