acid-base Flashcards
(34 cards)
pH and [H+]
inversely related
increase [H+], decrease pH (acidotic) - donate H+
decrease [H+], increase pH (alkalotic) - accept H+, give up OH-
strong acids vs. weak acids
strong: dissociate completely in soln
weak: dissociate partially
hydrogen functions
maintain cell membranes
helps with enzyme activity
component of H2O and keeps body hydrated
helps in energy production
hydrogen is a component of
sugars, proteins, starch, fats
where is the most acidic place in the body? why?
stomach bc HCl acid
*if HCl out of stomach - major damage
*duodenum has defense mechanisms to neutralize acid
*LES prevents movement of gastric acid into esophagus
what does acid-base balance affect?
electrolytes (Na, K, Cl)
hormones
oxygen transport and delivery
oxyhemoglobin dissociation curve
measures Hgb O2 saturation % (Y axis) to O2 partial pressure mmHg (x axis)
the human body can function for a short period of time out of what pH range before it becomes incompatible with life? survivable range?
pH < 6.8 or > 7.8 –> incompatible
7.2 -7.5 –> survivable
2 types of acids in the body
volatile and non-volatile acids
volatile acids
can be converted to gas
excreted by lungs
*carbonic acid (H2CO3)
*CO2 + H2O <–> H2CO3
non-volatile acids
cannot be converted to gas
excreted by kidneys
*phosphoric acid
*sulfuric acid
*acetoacetic acid
*beta-hydroxybutyric acid
*LACTIC ACID metabolized by body (liver + kidney)
buffers
chemicals in body that combine with acid or base to change pH
accept or release a H+
almost instantaneous, but short-lived
3 main buffer systems
- bicarbonate - carbonic acid buffer
- phosphate buffer
- protein buffers (Hgb)
bicarbonate
main ECF buffer
byproduct of cellular metabolism
combines with H2O = carbonic acid
in lungs: H2O + CO2
in kidneys: H + HCO3
what breaks down carbonic acid
carbonic anhydrase
^in many tissues of the body (esp. lungs+kidneys)
lungs
H2O + CO2
kindeys
H + HCO3
phosphate buffer
main ICF buffer
protein buffers
- carboxyl group (COOH) - weak acid, gives up H+
*amino acid
*acetic acid - amino group (NH2) - accept H+
*amino acids: carboxyl + amino group
*ammonia (NH3) - Hgb: picks up CO2 at cellular level
when H+ concentration increases…
pH decreases (acidic)
H+ moves INTO cells
more + charged ions IN cell
K+ moves OUT of cell
^electrical neutrality is restored inside cell
respiratory mechanisms
body produces CO2
CO2 + H2O = carbonic acid
exhaling excretes carbonic acid
^doesnt affect non-volatile acids (lactic acid)
how can the body pH be adjusted?
changing rate and depth of breathing
acidotic: increase rate/depth to blow off more CO2
alkalotic: decrease rate/depth to hold onto CO2
kidney excretion
can eliminate large amounts of acid (NOT carbonic acid)
can excrete bicarbonate
can conserve/produce bicarb ions
if kidneys fail, pH balance fails - depends on normal functions of renal system (because aren’t excreting H+ or base)
what is the most effective regulator of pH
kidneys
