Ion Product of water
Kw = [H+][OH-] = 1 x 10-14
In other words, the ion product of water is equal to the concentration of hydrogen ion multiplied by the concentration of hydroxide ion. The brackets stand for concentration so, if H+ stands for hydrogen ion, [H+] represents the concentration of hydrogen ion. The units are moles of the ion of concern per liter of water (molarity).
Any chemical species (molecule or ion) that is able to lose or "donate" a hydrogen ion (proton) in solution.
Any chemical species (molecule or ion) that is able to gain or "accept" a hydrogen ion (proton) in solution.
What is the difference between a strong acid and a weak acid?
Acids can be classified as weak acids or strong acids depending on their degree of dissociation into a hydrogen ion and a conjugate base (salt).
nearly completely dissociates into hydrogen ions and conjugate base in solution.
Strong acids are acids with a pKa < −1.74
only partially dissociates into hydrogen ions and anions (H+ and the conjugate base) in solution.
is a weak acid in equilibrium with its salt in solution that minimizes change in the pH of the solution when an acid or base is added to the solution.
cannot serve as a buffer because they are completely dissociated so they have no protons to donate when base is added to the solution and they cannot combine with protons when acid is added to the solution.
HA = H++ A-
[HA]= weak acid concentration, [A-]= conjugate base concentration, [H+]= proton concentration
Ka: dissociation constant, ::[HA]= weak acid concentration, [A-]= conjugate base concentration, [H+]= proton concentration
pH = pKa + log [A-]/[HA]
What are the two most important buffers in blood?
bicarbonate buffer system and hemoglobin buffer system
equations that show how the bicarbonate buffer system works in blood
CO2 + H2O <---> H2CO3 <---> HCO3- + H+
CO2 is constantly produced by metabolism and is exhaled by the lungs. Normally the lungs regulate the concentration of CO2 in the blood. Since the enzyme carbonic anhydrase is abundant in red blood cells, CO2 is readily converted to H2CO3, or carbonic acid. Since this happens so quickly, we treat the sum of CO2 and H2CO3 as if they were all in the form of CO2 or all in the form of H2CO3.
Respiratory compensation can be either Respiratory Acidosis or Respiratory Alkalosis and often occurs in response to Metabolic Alkalosis or Metabolic Acidosis, respectively.
occurs when the person breaths slower and/or shallower than normal so [H2CO3] (CO2)increases in the blood. If the denominator in the Henderson-Hasselbalch Equation increases, the pH must drop.
occurs when the person breaths faster and/or deeper than normal so [H2CO3] (CO2)decreases in the blood. If the denominator in the Henderson-Hasselbalch Equation decreases, the pH must rise.
If the pH of the blood drops to 7.3:
Assume that the drop in pH is due to metabolic acidosis. That is, some organic acid, say lactic acid, has been overproduced. The protons produced by the lactic acid are buffered by the bicarbonate buffer system, so the amount of bicarbonate has dropped. The excess carbonic acid produced has been exhaled by the lungs in the form of CO2. This initially resulted in a drop in the bicarbonate concentration and no change in the carbonic acid level
Compensatory Respiratory alkalosis is an attempt to
decrease the amount of H2CO3 (CO2), and in doing so bring up the ph. This is done by breathing faster and deaper.
compensatory respiratory acidosis
This increase in the carbonic acid term of the equation lowers the pH back towards normal.
To get over this and return to normal, The body must stop producing more bicarbonate than can normally be handled and the kidney must replace and get rid of the excess bicarbonate.
Insulin inhibits and glucagon increases the conversion of fatty acids into ketone bodies. Without insulin, ketone bodies are synthesized at a much faster rate than in a normal person. The ketone bodies are acids so, at high concentrations, they cause metabolic acidosis.
Fasting plasma glucose of a diabetic
level of suspected diabetic: 126 mg/dL (milligram/deciliter)or higher
A person is confirmed as diabetic when they have two or more fasting blood glucose tests of 126mg/dL or above.
Normal random (any time) plasma glucose levels should not be over
200mg/dL , a level over 200 mg/dL defines "overt" diabetes mellitus.
Normal fasting plasma glucose level:
can range from 70-100 mg/dL
When a patient is hyperventilating
More CO2 is expelled from the lungs so the denominator, PaCO2, in the PaCO2 form of the Henderson-Hasselbach equation must decrease.
If the denominator decreases, the value we take the log of increases, resulting in an increased pH. This is respiratory alkalosis.
When a hyperventilating patient breathes into a paper bag,
The exhaled CO2 is inhaled and not lost to the atmosphere. The body continues to make CO2 so the denominator, PaCO2, in the PaCO2 form of the Henderson-Hasselbach equation must increase.
If the denominator increases, the pH must decrease.
• It helps me to remember that pH is decreasing because H2CO3 (carbonic acid) and CO2 are acidic and acids have a low pH.
Hydrogen bonds are formed between hydrogen and ...
Oxygen or nitrogen
As the H+ concentration increases the ph ..
the undissociated acid usually ends in
the dissociated component of the acid end in
What are the three most common strong acids found in the human body?
Sulfuric acid H2SO4
Nitric Acid HNO3
Hydrochloric acid HCL
If the pH is greater than the pka then
The salt will be predominant
if the pka is greater than the pH then
the acid will be predominant
Formula for Carbonic Acid
Formula for Carbonate
What is the enzyme that converts carbonic acid to Carbonate
What causes diabetic metabolic acidosis?
an excess of Ketone bodies, an injection of insulin will keep the body from producing ketone bodies.
In the H-H equation what is the relationship between the denominator and the ph?
They are inverse
In the H-H equation what is the relationship between the numerator and the ph?
the two directly correlate
Duing metabolic acidosis what happens to the bicarbonate concentration?
it drops, in an attempted to buffer the the excess metabolic acid