Water & pH Flashcards
What is the property of water where its electrical charge is distributed asymmetrically about its structure?
Dipole
What property of water is responsible for its ability to decrease the force of attraction between charged and polar species?
Its HIGH DIELECTRIC CONSTANT
Water decreases the force of attraction between what species?
CHARGED and POLAR species
Of what significance is water’s high dielectric constant?
It decreases the force of attraction between POLAR and CHARGED species
What property of water is responsible for its ability to bind interact with an unshared electron pair on another SULFUR, OXYGEN, or NITROGEN atom?
Water can form HYDROGEN BONDS
What elements can form hydrogen bonds?
OXYGEN, SULFUR and NITROGEN
How many HYDROGEN BONDS can each molecule of liquid molecule associate with?
3.5 others
Hydrogen bonds formed by water are relatively weak with a half-life of what?
1 microsecond or less
What property of water is responsible for its ability to cleave AMIDE, ESTER or GLYCOSIDIC bonds?
Water is an excellent NUCLEOPHILE
What property of water is responsible for its ability to cleave bonds that hold biopolymers together?
Water is an excellent NUCLEOPHILE
Nucleophilic attack by water will cleave what kind of bonds?
AMIDE, ESTER and GLYCOSIDIC bonds that hold BIOPOLYMERS together.
What does water dissociate into?
HYDRONIUM and HYDROXIDE ions.
Define AMPHOTERIC
It acts as both an acid and a base.
Define AMPHIPATHIC
It has hydrophilic and hydrophobic parts
What property of water is responsible for its ability to be both an acid and a base?
Water is AMPHOTERIC.
What does it mean that water is AMPHOTERIC?
It acts as both an acid and a base.
Define pH
- It is the negative log of the HYDROGEN ION concentration
- measure of acidity or alkalinity
What is the normal pH of blood?
7.35 - 7.45
What determines the pH of blood?
CO2 and HCO3
ACIDS: proton donors or acceptors?
Acids are proton donors
BASES: proton donors or acceptors?
Bases are proton acceptors
ACIDS: high or low pH? pKa?
LOW pH & LOW pKa
BASES: high or low pH? pKa?
HIGH pH & HIGH pKa
ACID OR BASE: low pH & low pKa
ACID
ACID OR BASE: high pH & high pKa
BASE
Causes of HAGMA
"MUDPILES" Methanol Uremia DKA Paraldehyde pr Propylene glycol Isoniazid Lactic acidosis (Sepsis, Shock) Ethylene glycol Salicylates
What is used to calculate the concentration of a weak acid and its conjugate base?
Henderson-Hasselbach Equation
What is the Henderson-Hasselbach equation useful for?
- titration of amino acids
- predicting shifts in the bicarbonate system
- predicting distribution of drugs
What is used to calculate the titration of amino acids?
Henderson-Hasselbach Equation
What is used to predict shifts in the bicarbonate system?
Henderson-Hasselbach Equation
What is used to predict distribution of drugs?
Henderson-Hasselbach Equation
At what pH is a substance PROTONATED?
pH < pKa
At what pH is a substance DEPROTONATED?
pH > pKa
ACID or BASE: a substance is PROTONATED and UNCHARGED at pH < pKa?
ACID
ACID or BASE: a substance is PROTONATED and CHARGED at pH < pKa?
BASE
ACID or BASE: a substance is DEPROTONATED and CHARGED at pH > pKa?
ACID
ACID or BASE: a substance is DEPROTONATED and UNCHARGED at pH > pKa?
BASE
What is the pH if an ACID is PROTONATED and UNCHARGED?
pH < pKa
What is the pH if a BASE is PROTONATED and CHARGED?
pH < pKa
What is the pH if an ACID is DEPROTONATED and CHARGED?
pH > pKa
What is the pH if a BASE is DEPROTONATED and UNCHARGED?
pH > pKa
What is a buffer?
It is a mixture of a weak acid and its conjugate base that can resist a change in pH when protons are produced or consumed.
At what pH does maximum buffering occur?
+/- 1 pH unit from pKa
What is the most important extracellular physiologic buffer?
Bicarbonate
What is the most important intracellular physiologic buffer?
Proteins
What is a mixture of weak acid and its conjugate base that can resist a change in pH when protons are produced or consumed?
Buffers
Name 3 examples of physiologic buffers. Intracellular or extracellular?
- ) Bicarbonate - extracellular
- ) Proteins - intracellular
- ) Orthophosphate
Why is water is a universal solvent?
Its HIGH DIELECTRIC CONSTANT
What property of water means its charge is distributed asymmetrically about its structure?
Water is a DIPOLE
What percentage of body weight is water?
60%
What percentage of body weight is extracellular? Of total body water?
20% body weight
1/3 of the total body water
What percentage of body weight is intracellular? Of total body water?
40% body weight
2/3 of the total body water
What percentage of body weight is the interstitial fluid?
15%
What percentage of body weight is blood plasma?
5%
ER CASE of a 56/M CC: disorientation - fruity odor - CBG = 512 mg/dL What acid-base disorder will most likely be seen in the ABG?
High Anion Gap Metabolic Acidosis
What is the pH where 50% of species become DEPROTONATED?
pKa
