Basic Chemistry and Water: pH Flashcards Preview

Biochemistry: Exam 1 > Basic Chemistry and Water: pH > Flashcards

Flashcards in Basic Chemistry and Water: pH Deck (14):
1

What is pH?

A measure of free hydrogen ion concentration.

2

Why is pH important to biological systems?

It can affect electrostatic interactions (bonding), which can affect the structure and function of a biomolecule.

3

How can pH be calculated if you know [H+]?

pH = - log [H+]

4

What molecules does water dissociate into?

H+ and OH-

5

What is the term for the point at which the concentration of reactants and products is unchanging with time?

Equilibrium

6

What are the concentrations equilibrium concentrations of [H+] and [OH-} in water?

10^-7 M

7

What is the Keq of water?

10^-14

8

What is the molarity of water?

55.5 M

9

What is the pH of water?

7

10

What is the formula for calculating Ka?

Ka = [H+][A-] / [HA]

11

Which equation allows us to correlate pH with pKa?

Henderson Hasselbach

pH = pKa + log ([A-] / [HA])

12

When [A-] is equal to the [HA], what is pH?

pH = pKa

13

How does pH affect enzyme function?

If functional groups are not correctly protonated (i.e., are in the wrong pH), the enzyme will not function properly.

14

What are acid/base conjugate pairs that resist changes in pH?

Buffers