Chemistry of Water

Question 1

how many hydrogen bonds does each water molecule form with others

Answer 1

Each water molecule
forms hydrogen
bonds with 4 others

Question 2

what is the pH range for cell survival?

Answer 2

between 6.8 and 7.8

Question 3

what molecule gives up H+ when ionized?

Answer 3

an acid

Question 4

what is an example of a strong acid

Answer 4

HCL

Question 5

what molecule gives up OH-

Answer 5

a base

Question 6

what is an example of a strong base?

Answer 6

NaOH

Question 7

True or False. A weak acid will only partially ionize when added to water

Answer 7

true

Question 8

a species gains a proton (H+)

Answer 8

Protonation

Question 9

a species loses a proton

Answer 9

deprotonation

Question 10

T or F. The Henderson-Hasselbach equation only applies to weak acids or
bases

Answer 10

True

Question 11

when will something buffer best?

Answer 11

1.0 pH units above and below the pKa

Question 12

At a pH of 6.74 for acetic acid what is the ratio of salt/acid?

Answer 12

2=log(d/p)
2= log(20/1)

ratio is 20:1

Question 13

At a pH of 3.74 for acetic acid what is the ratio of salt/acid?

Answer 13

-1=log(d/p)
-1= log(1/10)

ratio is 1/10

Question 14

What is the intracellular buffer system?

Answer 14

Phosphate buffer system

Question 15

What is the RBC buffer system?

Answer 15

Hb buffer system

Question 16

What is the intracellular and plasma buffer system?

Answer 16

Proteins

Question 17

What is the extracellular fluid buffer system?

Answer 17

bicarbonate-carbonic acid buffer
system

Question 18

what form of phosphate is the best for intracellular?

Answer 18

H2PO4- + H+ and HPO42- + H+
Phosphates pka is about 7.2 for these forms

Question 19

Unusual properties of water

Answer 19

• high surface tension
• highest density at 4 C
• high heat capacity
• high heat of vaporization
• excellent solvent
• ionizes

Question 20

solvent

Answer 20

a liquid substance capable of dissolving other substances
- usually water

Question 21

pH scale

Answer 21

measures the amount of H+ ions in a solution

Question 22

acids

Answer 22

everything below a 7 on the pH
- they have more H+
- have few hydroxide ions (OH-)

Question 23

bases

Answer 23

everything above a 7 on the pH scale
- they have fewer hydrogens ion
- lots of OH-

Question 24

mixtures that can react with acids or bases to keep the pH within a particular range

Answer 24

a buffer

Question 25

enzyme that catalyzes the reaction between carbon dioxide and water to form carbonic acid

Answer 25

carbonic anhydrase

Question 26

carbonic acid is a _____ so it ionizes to form ______

Answer 26

carbonic acid is a weak acid so it ionizes to form bicarbonate

Question 27

Your blood brings bicarbonate to your lungs and it is exhaled as ______

Answer 27

carbon dioxide

Question 28

How is bicarbonate formed?

Answer 28

CO2 + H2O -> (carbonic anhydrase) -> HCO3- + H+
carbonic acid (pronated) dissociates into bicarbonate (deprotonated) and H+

Question 29

solute

Answer 29

a substance that dissolves
- ions, molecules, atoms

Question 30

BICARBONATE-CARBONIC ACID has a pka of

Answer 30

6.1
- it will best buffer at 5.1 and 7.1

Question 31

what is the pH of blood?

Answer 31

7.4

Question 32

When _____ is produced as a result of fuel oxidation it will
dissolve and be converted to _______ by carbonic anhydrase in the red blood cell. _______ will ionize and be exported in the plasma via the ______.

Answer 32

When CO2 is produced as a result of fuel oxidation it will
dissolve and be converted to H2CO3 by carbonic anhydrase in the red blood cell. H2CO3 will ionize and be exported in the plasma via the HCO3-/Cl transporter

Question 33

With hyperventilation, the blood pH increases. Why?

Answer 33

When a person hyperventilates they exhale more carbon dioxide than normal. As a result, the carbon dioxide concentration in the blood is reduced and the bicarbonate/carbonic acid equilibrium shifts to the left

Increase in pH = fewer hydrogen ions

Question 34

How does low pH affect cells?

Answer 34

Not only do changes in pH alter the way in which cells metabolize and grow, it can also change the physical structure of the cells themselves.

AND SHAPE IS EVERYTHING