Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > Biochemical Buffers And Regulation Of Body PH > Flashcards

Biochemical Buffers And Regulation Of Body PH Flashcards

1
Q

Tissue pH

A

7.40

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Organs that have role in regulating pH

A

Lungs and kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

PH equation

A

pH = -log10 [H+]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Change in one pH unit represents _____ change in [H+]

A

10-fold change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

T/f strong acids and bases ionize completely in dilute aqueous solutions

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Degree of dissociation of weak acid depends on ____

A

Value for Ka

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Weak acids in body

A

. Amino acids
. Fatty acids
. Lactic acid
. Ammonium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Weak bases in body

A

. Lactate
. Acetate
. Ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Henderson-Hasselbalch equation

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a buffer

A

. Solution that resists a change in pH when either acid or base is added
. Mixture of weak acid and conjugate base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When does a buffer work best and why?

A

. Composed of equal amts of HA and A-

. Any added strong base can combine w/ weak acid and be neutralized and vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When do you lose buffering power?

A

. Depleted conjugate acid or conjugate base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Smallest changes in pH occur with a buffer when ___

A

Addition of acid/base to a buffer whose pH is in the region of the pK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When [HA] = [A-] then pH = ____

A

pK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Best buffering range for conjugate pair

A

.pK +/- 1pH unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is pH regulation important to our health

A

. Enzymes and proteins function in specific pH ranges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Acceptable range pH for arterial plasma pH and consistent range w/ life

A

. Acceptable: 7.40 +/- 0.05

. Life: 6.8-7.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Sources of acids and bases in body

A

. Glucose and fatty acid oxidation generate CO2 and H2O

. Metabolism generates organic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Primary buffer system in body

A

Bicarbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Bicarbonate equation

A

CO2 (gas) -> CO2 (dissolved) + H2O H2CO3 H + HCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Important players in bicarbonate buffer system

A

. carbonic acid (H2CO3)
. Bicarbonate/base (HCO3-)
. CO2 acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

K1 in bicarbonate rxn

A

[H2CO3]/[CO2][H2O}

23
Q

K2 in bicarbonate rxn

A

[H+][HCO3-]/[H2CO3]

24
Q

How is bicarbonate rxn K1 equilibrium maintained?

A

Carbonic anhydrase

25
Q

WHen bicarbonate rxn K1 lies to the left there’s more ___

A

CO2 than H20 (400 times more)

26
Q

When K2 lies to the right in bicarbonate rxn there mor e____

A

HCO3, not much H2CO3

27
Q

Final equation for find bicarbonate pH

A

pH = 6.1 + log ([HCO3]/[CO2])

28
Q

How does buffer w/ pK of 6.1 act as effective buffer at pH 7.4?

A

Open system and acid and base can be added/substrate as needed

29
Q

Why does [HCOs]/[CO2] ratio not change much?

A

Human body secretes CO2 as gas in lungs but then is replenished by metabolism of fuels in tissues
. CO2 dissolved is in equilibrium w/ CO2 gas
. Kidneys can retain or excrete base HCO3 as needed

30
Q

Does carbonate buffer system have more conjugate base or acid and what does this mean?

A

Base, it can buffer additions of acid better than additions of base

31
Q

Conversion factor of CO2 anew hy is it needed

A

[CO2] in mmol/L = 0.03 [CO2 mmHg]

Needed to do Henderson-Hasselbalch so CP2 is in same units as bicarbonate

32
Q

T/F CO2 is not soluble in aqueous environments?

A

T

33
Q

How is CO2 transported from tissues to lungs?

A

. Generated in tissues during catabolism of fuels to generate ATP
. Converted to very soluble bicarbonate (HCO3) that is carried to lungs

34
Q

What occurs w/ CO2 in tissues

A

. CO2 diffuses into erythrocyte
. Carbonic anhydrase catalyzes hydration of CO2 and H2O which dissociates to release H+ and HCO3-
. Cl-HCO3 exchanges (band 3 antiport transporter) exports HCO3 while importing CL to maintain electrical neutrality

35
Q

CO2 in the lung

A

.dissolved CO2 exhaled
. Law of mass action moves carbonic anhydrase in opposite direction
. Brings HCO3 into erythrocyte to form CO2 which can cross membrane to be exhaled

36
Q

Respiratory acidosis

A

. Lungs aren’t excreting enough acid as CO2
. Acid accumulates in blood and pH drops
. Ex: blocked airway, emphysema, COPD

37
Q

Respiratory alkalosis

A

. Lungs excrete too much acid as CO2 causing inc. in blood pH
. Ex: hyperventilation

38
Q

Metabolic acidosis

A

. Body generates too much acid that can’t be excreted by lungs
. ex:lactic acid, diabetic ketoacidosis, oral ingestion of acid

39
Q

Metabolic alkalosis

A

. Someone has alkaline blood and it not result of respiratory imbalance
. Ex: excess vomiting of stomach contents, ingestion of antacids

40
Q

Compensation for pH

A

. Involves changes in lung and kidney

. Metabolic imbalance compensated w/ respiratory and vice versa

41
Q

Body pH regulators and how quickly they can mediate

A

. Buffers: accommodate acid/ base additions almost immediately
. Lungs: respiratory rate via loss/retention of CO2 in minutes
. Kidneys: regulates loss of H, ammonia, bicarbonate, and others in matter of minutes to hours

42
Q

Serum EBAL

A

. Anion gap
. EBAL = [Na] - ([Cl] + [HCO3])
. Represents differences btw total primary cations and anions measured in blood
. Sometimes K included

43
Q

high anion gap is typical of ____

A

Metabolic acidosis

44
Q

Stomach pH

A

1-3

45
Q

Small intestine pH

A

6-8

46
Q

Where are drugs absorbed best across membranes?

A

. At pH where dissociation of side chain results in neutral molecule since drugs go through protein transporters or hydrophobic nature of neutral molecule allows it to pass through membrane

47
Q

Acidic amino acid (aspartic acid) side chain pK value

A

3.9

48
Q

Basic amino acids (arginine) pK value

A

6.0

49
Q

Insulin characteristics

A

. Small protein, net charge -1.8
. Naturally water soluble
. Degraded rapidly in body

50
Q

Insulin glargine characteristics

A

. Less water soluble due to charge closer to 0 (+0.2)
. Injected subcutaneously and precipitates at pH of body
. Dissolves slowly over time causing better long term glycemic control and fewer injections

51
Q

How to distinguish btw respiratory and metabolic acidosis

A

. If respiratory, CO2 and [HCO3] will also be high

. If metabolic then [HCO3] will be low and [CO2] will be low

52
Q

How to distinguish btw respiratory and metabolic alkalosis

A

. Respiratory then [CO2] and [HCO3] will be low

. Metabolic only through consumption of base of vomiting a ton

53
Q

What if pH is normal but [CO2] and [HCO3] are not w/in normal range?

A

. Underlying pH disorder that is being compensated
. High edge of normal pH is alkalosis
. Low edge of normal pH is acidosis

Biochemistry (64 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions