Chapter 2: Additional Slides

Question 1

first line of defense against pH shift

Answer 1

chemical buffer system

Question 2

second line of defense against pH shift

Answer 2

physiological buffers

Question 3

chemical buffer systems

Answer 3

1. bicarbonate buffer system
2. phosphate buffer system
3. protein buffer system

Question 4

physiological buffers

Answer 4

1. respiratory mechanism
2. renal mechanism

Question 5

respiratory mechanism

Answer 5

CO2 excretion

Question 6

renal mechanism

Answer 6

H+ excretion

Question 7

bicarbonate buffer maintain a __:__ ratio of bicarbonate to carbonic acid

Answer 7

20:1

Question 8

bicarbonate

Answer 8

HCO3-

Question 9

carbonic acid

Answer 9

H2CO3

Question 10

what do lung eliminate

Answer 10

carbon dioxide

Question 11

what can kidneys remove

Answer 11

excess non-gas acids and bases

Question 12

enzyme that assists rapid inter-conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions

Answer 12

Carbonic anhydrase

Question 13

where are carbonic anhydrase found

Answer 13

• red blood cells
• gastric mucosa
• pancreatic cells
• renal tubules

Question 14

to lower pH, kidneys excrete

Answer 14

HCO3-

Question 15

to raise pH, kidneys excrete __ and lungs excrete __

Answer 15

• H+
• CO2

Question 16

sodium bicarbonate

Answer 16

NaHCO3

Question 17

when can carbonic acid buffer system only function

Answer 17

respiratory system and respiratory control centers are working normally

Question 18

ability to buffer acids is limited by what?

Answer 18

availability of bicarbonate ions

Question 19

what is the pKa of carbonic acid

Answer 19

6.35

Question 20

pH of blood

Answer 20

7.4

Question 21

has a much larger capacity of resisting change in pH

Answer 21

more concentrated buffer

Question 22

major buffer system of the body

Answer 22

bicarbonate buffer

Question 23

very effective but not found in high concentrations in extracellular fluid

Answer 23

phosphate buffer

Question 24

where is the phosphate buffer important

Answer 24

• intracellular fluid (ICF)
• renal tubules

Question 25

optimum pH of phosphate

Answer 25

6.8

Question 26

What are the two types protein buffers

Answer 26

1. amino acids 2. hemoglobin

Question 27

respond to pH changes by accepting or releasing H+

Answer 27

free and terminal amino acids

Question 28

amino acids: if acid comes into blood, hydronium ions can be neutralized by what group

Answer 28

-COO-

Question 29

amino acids: if base is added, it can be neutralized by what group

Answer 29

-NH3+

Question 30

- binds CO2 - binds and transports hydrogen and oxygen - maintains blood pH as it changes from oxyhemoglobin to deoxyhemoglobin

Answer 30

hemoglobin

Question 31

hemoglobin maintains pH as it changes from what to what?

Answer 31

- oxyhemoglobin - deoxyhemoglobin

Question 32

- exhalation of CO2 - only works in volatile acids - does not affect fixed acids - pH can be adjusted by changing rate and depth of breathing - provide O2 to cells and remove CO2

Answer 32

respiratory regulation

Question 33

respiratory regulation only works on what acids

Answer 33

volatile acids

Question 34

respiratory regulation equation

Answer 34

CO2 + H2O <-> H2CO3 <-> H+ + HCO3-

Question 35

- drives reaction to the left - caused removal of H+ - pH goes up

Answer 35

hyperventilation

Question 36

- drives reaction to the right - additional of H+ - pH goes down

Answer 36

hypoventilation

Question 37

- can eliminate large amounts of fixed acid - excrete base - conserve and produce bicarbonate ions

Answer 37

renal regulation

Question 38

renal regulation is the __ __ regulator of pH

Answer 38

most effective

Question 39

primary base in the body

Answer 39

HCO3

Question 40

for every hydrogen ion buffered by bicarbonate - a __ __ is consumed

Answer 40

bicarbonate ion

Question 41

where is the bicarbonate freely filtered

Answer 41

glomerulus

Question 42

approx. how many bicarbonate would be filtered in 24 hours

Answer 42

4300mmol

Question 43

what happens when re-generation of bicarbonate would not happen

Answer 43

cause acidotic state

Question 44

Renal Bicarbonate Regeneration involves what enzyme

Answer 44

carbonate dehydratase (carbonic anhydrase)

Question 45

catalyses the formation of CO2 and H2O from carbonic acid (H2CO3) in the renal tubular lumen

Answer 45

carbonate dehydratase

Question 46

CO2 diffuses across the __ __ into the __ __

Answer 46

- luminal membrane - tubular cells

Question 47

renal response to acidosis

Answer 47

1. increased reabsorption of filtered HCO3- 2. increases excretion of titratable acids 3. increased production of ammonia

Question 48

titratable acids excreted in urine during acidosis

Answer 48

H2PO4- (Dihydrogen phosphate)

Question 49

principal source of NH3 production in the kidneys

Answer 49

deamination of glutamine

Question 50

when body is in alkalosis, tubular cells secrete __ __ and reclaim __ __

Answer 50

- bicarbonate ions - hydrogen ions

Question 51

the amount of strong base needed to titrate the urine pH back to 7.4.

Answer 51

Titratable acid (TA)