Acid base part 3

Question 1

CO2 is transported in the blood as 1 of 3 things:

Answer 1

1) CO2
2) Carbonic acid H2CO3
3) Bicarbonate ion HCO3-

Question 2

What is the most important buffer system in the ECF?

Answer 2

Bicarbonate buffer system

Question 3

The Bicarbonate buffer system consists of:

Answer 3

a weak acid H2CO3, and a weak base HCO3-

Question 4

Is bicarb readily available?

Answer 4

yes

Question 5

What makes bicarb an open system?

Answer 5

because the components of the bicarb system can be used independently of each other.
-Example: CO2 by the lungs and Bicarb by the kidneys

Question 6

What organ produces bicarb?

Answer 6

The pancreas

Question 7

What is the carbonic acid reaction? Is it slow or fast?

Answer 7

CO2 + H2O = H2CO3

this reaction is slow without an enzyme

Question 8

bicarbonate reaction

Answer 8

Dissociation of H2CO3 = H+ + HCO3-

Question 9

What is the bicarbonate/carbonic acid reaction called? is it reversible?

Answer 9

Hydration reaction

The reaction is reversible

Question 10

what enzyme catalyzes the carbonic acid reaction?

Answer 10

Carbonic anhydrase

Question 11

Where is carbonic anhydrase abundant?

Answer 11

1) Within red blood cells
2) ln the walls of lung alveoli
3) epithelial cells of renal tubules

Question 12

Where is phosphate buffer important?

Answer 12

1) intracellularly

2) tubular filtrate of the kidneys

Question 13

What is the weak acid and conjugate base of phosphate buffer?

Answer 13

weak acid, monosodium phosphate, NaH2PO4

conjugate base, disodium phosphate, Na2HPO4

Question 14

what happens to phosphate buffer when it reacts with a strong acid?

Answer 14

• a weaker acid and salt is formed

HCl + Na2HPO4 = NaH2PO4 + NaCl

Question 15

what happens to phosphate buffer when it reacts with a strong base?

Answer 15

• a weaker base and water is formed

NaOH + NaH2PO4 = Na2HPO4 + H2O

Question 16

What is the second line of defense for acid-base balance?

Answer 16

the lungs (the respiratory system) (fast)

Question 17

Which system has more capacity to buffer? Respiratory or chemical systems?

Answer 17

Respiratory

Question 18

What is the third line of defense for acid-base balance?

Answer 18

the kidneys (slow)

Question 19

What is the most potent acid-base regulator?

Answer 19

the kidneys - takes days to respond

Question 20

How do the kidneys help acid-base?

Answer 20

excretes basic or acidic urine

• creates HCO3-
• filtrates bicarb HCO3-
• secretes a lot of H+

Question 21

how do kidneys add to real loss of acid or base?

Answer 21

changes in the amount of HCO3- filtered

changes in the amount of H+ secreted

Question 22

How do the kidneys regulate [H+] in the ECF? (3 ways)

Answer 22

1) Secrete H+
2) Reabsorbs filtered HCO3-
3) Production of new HCO3-

Question 23

Secretion of H+ occurs in the epithelial cells of 3 places:

Answer 23

1) proximal tubes (mostly)
2) distal tubules
3) collecting ducts