MBB 222 Wk2-1 Notes: Buffers & Protonation

Fill-in-the-blank flashcards covering hydrolysis of amides, protonation, buffers, Henderson-Hasselbalch, lactic acid, and phosphate buffering concepts from Week 2 notes.

Hydrolysis of an amide with water yields a carboxylic acid and an .

amine

The conjugate acid is the protonated form; the conjugate base is the form.

deprotonated

The acid dissociation constant Ka is defined as Ka = .

[base][H+]/[acid]

A buffer is most effective when pH is near the molecule's .

pKa

Total lactic acid is the sum of the species.

acid and base

At pH 4.4, with pKa 3.86 and 100 mM total lactic acid, the acid (carboxylic) form is approximately mM.

22

The Henderson-Hasselbalch equation is pH = pKa + log10 .

[base]/[acid]

The protonation fraction fproton is given by fproton = [H+]/([H+] + ).

Ka

A 50% protonated condition occurs when pH equals the molecule's .

pKa

Near neutral pH, the phosphate buffering pair is H2PO4− and HPO4^2− with pKa around .

7.2

Blood pH is approximately 7.4, with lactic acid pKa 3.86, giving a base-to-acid ratio of about .

3500

At physiological pH, phosphate species have at least one charge.

negative

Phosphate has three dissociable protons; the second dissociation has pKa = .

7.2

A buffer's buffering capacity is strongest when the pH is within one unit of its .

pKa

In biochemistry, pH is an input and the molecule's protonation state is the .

output