Physiological pH Buffers

Question 1

T/F: [ ] of a gas is = to the pressure of the gas

Answer 1

T

Question 2

The [ ] of any gas in fluids will be expressed in terms of _____

Answer 2

pressure (P)

Question 3

Borderline hemoglobin saturation to support normal brain function:

Answer 3

85%

Question 4

More acidic pH for hemoglobin leads to…

Answer 4

decrease in oxygen carrying ability

Question 5

Factors that influence pH:

Answer 5

• physical activity
• metabolism
• protein degradation
• diseases
• diseases of lungs and kidneys
• drugs

Question 6

How does physical activity affect pH?

Answer 6

• muscles produce lactic acid which is excreted in urine
• excessive exercise can results in large amounts of lactic acid and kidneys can’t excrete it
• pH will drop

Question 7

How does metabolism affect pH?

Answer 7

• can release acids or bases

- ex: protein degradation creates ammonia (base)

Question 8

How do diseases (ex: diabetes) affect pH?

Answer 8

• can’t make enough insulin
• oxidize fats instead of carbs: makes acid
• not well controlled diabetes = drop in pH

Question 9

How do diseases of lungs and kidneys affect pH?

Answer 9

• cause pH to change b/c these organs are highly involved in regulating pH

Question 10

How do drugs affect pH?

Answer 10

• large number of drugs available to treat different types of diseases are either acidic or basic

Question 11

Arrhenius theory:

Answer 11

• acid: release H+ when placed in water

- base: releases OH- when placed in water

Question 12

Bronsted Lowry theory:

Answer 12

• acid: donates H+
• base: accepts H+
• reaction is reversible
• conjugate acid: comes from the base
• conjugate base: comes from the acid

Question 13

Lewis theory:

Answer 13

• acid: accepts pair of e-

- base: donates pair of e-

Question 14

pKa and pKb measures the strength of…

Answer 14

acids and bases

- tells us how much H+ of acid or OH- of base is released

Question 15

More H+ released in solution = ______

Answer 15

stronger the acid

Question 16

More OH- released in solution = _____

Answer 16

stronger the base

Question 17

Ka = (formula)

Answer 17

[ionized form]/[unionized form]

Question 18

Relationship between Ka and strength of acid:

Answer 18

direct relationship

Question 19

pKa is the _______ of Ka

Answer 19

negative log

Question 20

Stronger acids will have a _____ pKa

Answer 20

smaller

Question 21

Relationship between pKa and acid strength:

Answer 21

inverse relationship

Question 22

Buffers help keep pH of solution…

Answer 22

constant

Question 23

pH of body:

Answer 23

7.4

Question 24

Buffers are made up of..

Answer 24

weak acid and its salt (vice versa w/ base)

Question 25

Def of salt:

Answer 25

charged compound that contains anion of acid/cation of base | - results from reaction between acid and base

Question 26

Acetate buffer is an...

Answer 26

acidic buffer

Question 27

Ammonia buffer is a...

Answer 27

basic buffer

Question 28

Mixing of acid and base together results in...

Answer 28

water and base

Question 29

Neutral form:

Answer 29

not charged

Question 30

Protonated form:

Answer 30

has H+ attached (no charge)

Question 31

Deprotonated form:

Answer 31

loses H+ (positive charge)

Question 32

Midpoint of titration:

Answer 32

- max resistance range - equal amounts of salt and acid/base - pKa/pKb of acid/base

Question 33

Why would a pH not change as much after the initial addition of a base to an acidic solution?

Answer 33

solution now has some salt in it, which creates a buffering system that will resist changes in pH

Question 34

More salt created in a solution =

Answer 34

more resistance to change until there are no more of initial solution molecules left

Question 35

T/F: to buffer a solution at specific pH, select acid/base whose pKa is greater than or equal to target pH

Answer 35

T

Question 36

Henderson buffer equation for acids:

Answer 36

pH = pKa + log[Ac-]/[HAc]

Question 37

Henderson buffer equation for bases:

Answer 37

pH = pKw-pKb+log[B]/[HB+]

Question 38

Two ions that are in the blood that act as physiological buffers:

Answer 38

- carbonic acid (H2CO3) | - dihydrogen phosphate (H2PO4-)

Question 39

Carbonic acid has a pKa of...

Answer 39

6.1

Question 40

Salt of carbonic acid is...

Answer 40

- bicarbonate anion (HCO3-)

Question 41

Dihydrogen phosphate has a pKa of...

Answer 41

6.7

Question 42

Salt of dihydrogen phosphate is...

Answer 42

HPO42-

Question 43

Dihydrogen phosphate loses ____ protons

Answer 43

3 | - titration curve has 3 midpoints

Question 44

T/F: [dihydrogen phosphate} is high, so it has a high buffering power in regulating pH

Answer 44

F, has low [dihydrogen phosphate] so it has limited buffering power

Question 45

Bicarbonate ion plays a _____ important role in regulating pH than dihydrogen phosphate

Answer 45

more important | - more [bicarbonate]

Question 46

Acidosis:

Answer 46

pt have blood pH less than 7.4

Question 47

2 causes of acidosis:

Answer 47

- respiratory | - metabolic

Question 48

Respiratory issues (diseases of lung/respiratory system) can cause acidosis b/c...

Answer 48

may not be able to efficiently eliminate CO2 from blood and will drop pH

Question 49

Metabolic issues (exercise/diabetes) can cause acidosis b/c...

Answer 49

- release of acidic substances into blood stream from organs

Question 50

Alkalosis:

Answer 50

pt have blood pH greater than 7.4

Question 51

T/F: hyperventilation causes alkalosis

Answer 51

T

Question 52

Vomiting, excess intake of Tums/baking soda causes...

Answer 52

- alkalosis | - eliminates excessive amounts of H+

Question 53

Kidney disease causes alkalosis b/c...

Answer 53

- body can't eliminate excessive amounts of bicarb

Question 54

Alkalosis impairs...

Answer 54

calcium ion balance, which leads to muscle cramps and cardiac arrhythmia