Week 2 - Protonation Buffers and Nucleic Acids

Flashcards covering protonation, buffers, the Henderson-Hasselbalch equation, and the basic structure of nucleic acids from the lecture notes.

The fraction of a molecule's population that is protonated depends on its molecular structure (pKa) and the __ it is in.

environment (pH)

A buffer exists when both the conjugate acid and __ species are present in high amounts and similar proportions.

conjugate base

A low pH generally results in a __ protonation fraction for a compound.

high

A high pH generally results in a __ protonation fraction for a compound.

low

When the pH equals the pKa of a molecule, it is __ protonated.

50%

If the pH is much lower than a compound's pKa (by more than 2 units), it is essentially all __.

protonated

If the pH is much higher than a compound's pKa (by more than 2 units), it is essentially all __.

deprotonated

A buffer acts like a sponge; any H+ consumed will be __ by the buffer's conjugate acid species.

replaced

A buffer acts like a sponge; any new H+ produced will be __ by the buffer's conjugate base species.

absorbed

Good buffers are characterized by possessing significant quantities of both a conjugate acid and its .

conjugate base

The __ equation is used to determine if a solution is a good buffer by assessing the ratio of conjugate base to acid at a given pH.

Henderson-Hasselbalch

With a pKa of 7.2, __ is an effective buffer in the human body, especially inside cells.

phosphate

The two dominant phosphate species that effectively buffer around physiological pH are H2PO4- and __.

HPO4^2-

A nucleotide fundamentally consists of three parts: a sugar, a phosphate, and a __.

nucleobase

These components form the structural backbone of a nucleotide.

sugar, phosphate

In a nucleotide, the __ is also commonly referred to as the sidechain.

nucleobase