Water & pH 😄

Question 0

Predominant chemical component of living organisms

The molecule that is irregular, slightly skewed tetrahedron: oxygen at its center, 2 hydrogens and the unshared electrons occupy the corners

Dipole ( a molecule with electrical charge distributed asymmetrically by its structure)

High dielectric constant (water greatly decreases the force of attraction between charged and polar species)

Hydrogen bond (an unshield hydrogen nucleus covalently bound to an electron-withdrawing oxygen, nitrogen or sulfur atom can interact with an unshared electron pair on another sulfur, oxygen or nitrogen atom ; on average, each molecule in liquid waters associates through hydrogen bonds with 3.5 others; relatively weak and transient, with a half-life of one microsecond or less; nucleophilic attack by water generally results in the cleavage of the amide, glycoside, or ester bonds that hold biopolymers together.

Amphoteric (it can dissociate into hydronium and hydroxide ions; water is both an acid and a base)

Answer 0

Water

Question 1

Negative log of the hydrogen ion concentration

Measure of acidity or alkalinity

Answer 1

pH

Question 2

Acids are proton donors

Bases are protons acceptors

Answer 2

Acids and bases

Question 3

Used to calculate the concentration of a weak acid (HA) and its conjugate base (A-)

Useful for: titration of amino acids, predicting shifts in the bicarbonate buffer system, predicting distribution of drugs

Answer 3

Henderson-Hasselbalch Equation

Question 4

Mixture of weak acid and its conjugate base that can resist a change in pH when protons are produced or consumed

Mixture buffering occurs +1 pH unit from pKa

Physiologic buffers:

1. Bicarbonate - most important EXTRACELLULAR
2. Proteins - most important INTRACELLULAR
3. Orthophosphate

Answer 4

Buffers

Question 5

Causes of high anion gap metabolic acidosis

Answer 5

Methanol
Uremia
Diabetic Ketoacidosis
Paraldehyde and Propylene Glycol
Isoniazid 
Lactic acidosis (septic, shock)
Ethylene Glycol
Salicylates

Question 6

Chemical compound that has a total net charge of zero

Answer 6

Zwitterion

Question 7

PH at which the zwitterion is the predominant form of a chemical compound

Answer 7

Isoelectric pH