Acid/Base Regulation Flashcards
What is amphoteric
Capable of donating and accepting protons
What is diprotic
Possessing two dissociable protons
What are zwitterions
A dipolar ion, with spatially separated positive and negative charges
What is isoelectric point
the pH at which a solute has no electric charge
What is pH derived from
the ionization of water
What does it mean to end with -ic acid
Acid expressed as free acid
What does it mean to end with -ate
Ionized conjugate base expressed. This is more acceptable under physiologic conditions
What is Ka?
a dissociation constant that tells the tendency of an acid to give up a proton
Strong acids have a strong tendency to _____ and thus a lower _____
dissociate; pka
When equal amounts of free acid and conjugate base are present : [HA] = ____
[A-]
All amino acids have at least ____ dissociable protons
2
What does a titration curve for glycine and other uncharged amino acids look like
pk1= 2.34 and pk2= 9.60
For acidic amino acids like glutamate and aspartate you get ____equivalents to give off because they have an extra charge side group
3
What does a titration curve for acidic amino acids like glutamate and aspartate look like
pk1= 2.19 pkR= 4.25 pk2= 9.67
What is unusual about the aa Histidine?
It is a basic aa that doesnt have a codon in the genetic code. It serves as a good H sensor. It’s pkR = 6 whereas in other aa pkR= 10
What does cysteine serve as
an oxidative stress sensor. It forms and breaks disulfide bonds under oxidative stress conditions
Why do drug pKa’s need to be neutral
To pass through membranes
How does pH dropping affect drug delivery
Drug becomes less affective. You need to use a lot more
What are peptide bonds. How are they formed?
amide bonds. They are formed by dehydration reactions
Formation of a peptide bond removes the (-) and (+) charges of the _____ and ___ groups involved
caryboxyl and amino
Overall charge of a protein is dependent on:
- The number of amino acids with charged R groups
2. the pH of the surroundings
What is the intracellular fluid and urine dependent on
phosphate buffer and proteins
What is the extracellular fluid and blood dependent on
bicarbonate buffer and proteins
At physiological pH (7.0) the predominant form of the phosphate buffer system is the ______
conjugate base (proton acceptor)
What is pH above 7.45 called
Alkalemia
What is pH below 7.35 called
Acidemia
What is acidosis
The process of becoming acidemic
What is alkalosis
the process of becoming alkalemic
How does acidosis or alkalosis happen
may be the result of respiratory or metabolic problems
What is the major biological buffer of the blood
bicarbonate
Why is CO2 considered to be an acid
It forms with water to form carbonic acid
pH below _____ is lethal
6.8
pH above ____ is lethal
7.8
What is normal pH
7.4
What is the ratio of bicarbonate buffer system to the phosphate buffer system
20:1
How do you interpret arterial blood gas
- History and physical
- Look at the pH
- Look at PCO2 and HCO3-
a. Distinguish initial change from compensatory response
b. Intial change will be the abnormal value that correlates with the abnormal pH
What is the initial chemical change and compensatory response for respiratory acidosis
High PCO2 and high HCO3-
What is the initial chemical change and compensatory response for metabolic acidosis
Low bicarbonate and low PCO2
What is the initial chemical change and compensatory response for respiratory alkalosis
Low PCO2, low bicarbonate
What is the initial chemical change and compensatory response for metabolic alkalosis
High bicarbonate; and high PCO2
What happens when you breathe slowly
You hold in more CO2, so your lungs decrease the amount of acid to compensate
what does hypoventilation mean
Less C02 is being released. PCO2 increases, blood pH decreases
What does hyperventilation mean
More CO2 is released; PCO2 decreases, blood pH increases
What are some common causes of respiratory acidosis
Emphysema and depressed CNS respiratory center
What are some common causes of respiratory alkalosis
Hysteria/hyperventilation, or high altitude
What are some common causes of metabolic alkalosis
antacid abuse or excessive vomiting
What are common causes of metabolic acidosis
diabetic ketoacidosis or lactic acidosis
