Chapter 2.5: pH and Biological Buffers

Question 1

What is the purpose of a buffer?

Answer 1

to maintain intracellular and extracellular pH within a very narrow range and resist changes in pH in the presence of internal and external influences
–> a solution that resists change in pH when small amounts of strong acid or base are added

Question 2

What is a buffer made from?

Answer 2

 a weak acid and its conjugate base or
 a weak base and its conjugate acid

Question 3

How do buffers work?

Answer 3

Buffers work by chemically tying up acid and base

Question 4

What is buffer capacity?

Answer 4

Defined as the moles of an acid or base necessary to change the pH of a solution by 1

Question 5

What is acidosis?

Answer 5

pH < 7.35
* Depression of respiratory rate causes an increase in carbon dioxide in the blood, leading to lowered pH
* i.e. morphine overdose

Question 6

What is alkalosis

Answer 6

pH > 7.45
* Hyperventilation causes a decrease in carbon dioxide in the blood, leading to a higher pH
* i.e. asthma attack

Question 7

What are three weak interactions found in biochemical systems?

Answer 7

1. ionic bonds
2. hydrogen bonding
3. van der waals

Question 8

Explain ionic bonds

Answer 8

Electrostatic interactions take place between ions having opposite charges. The strength of electrostatic interactions depends on the nature of the medium

Question 9

explain hydrogen bonding

Answer 9

a hydrogen atom is covalently bonded to an electronegative atom, such as oxygen or nitrogen.
Hydrogen bonds in biomolecules are weakened in the presence of water because water readily forms hydrogen bonds.

Question 10

explain van der waals

Answer 10

take place when the transient asymmetry of charges on one nonpolar molecule induces complementary asymmetry in nearby nonpolar molecules

Question 11

is entropy of the universe increasing or decreasing

Answer 11

Increasing

Question 12

What is the pH of a solution

Answer 12

a measure of hydrogen ion concentration and is an important parameter in biochemical systems, both in vivo and in vitro

Question 13

what is a buffer

Answer 13

are acid–base conjugate pairs that resist changes in pH