Molecules of Life Flashcards
Biomedical Importance of Water
- Water is a reactant in metabolic and enzymatic reactions.
- Water regulated by Anti-Diuretic Hormone (Vasopressin) and evaporative loss
- Body Water function of age, body mass, and body fat
- Body water mass declines with age
Molar Concentration of Water
55.6 M
Dissociation Constant of Water
1x10^-14
Henderson-Hasselbalch Equation
pH = pKa + log [A-]/[HA]
Why can aspirin be easily absorbed into the blood from the stomach?
At pH 1.5, it is protonated and neutral charged
Composition of Buffers
Mixture of a weak acid and its conjugate base
Physiological Phosphate Buffer
H2PO4- HPO42-
Bicarbonate Buffer
CO2 + H20 H2CO3 (E: carbonic anhydrase)
H2CO3 H+ + HCO3-
How is [CO2] measured in the body?
pCO2 (alveolar air) * 0.03 mM/mm Hg gives arterial plasma concentration
Three Ways to Regulate pH
H+ + HCO3- H20+CO2 (Lungs)
H+ + HPO42- H2PO4- (kidneys)
H+ + NH3 NH4+ (kidneys)
Isohydric Transport
Transport of CO3 without generating a change in blood pH