Biochemistry - Lecture 1 - Acids/bases

Front 1

Acid/Base Equation

What happens if you add a strong base?

Back 1

HA<->H+ + A-

system will move right - more H+ will form so it can react with the OH

Front 2

Buffers

H&H Equation

Back 2

Regulate pH inside and outside cells. solution of weak acid and its conjugate base

pH= pka +log [CB/HA]

Front 3

pka represents pH at which a weak acid is ____ dissociated

Back 3

50 percent

Front 4

what are 2 system constraints of weak acid buffer systems?

Back 4

1. weak acids only buffer at pH near their pKa.
2. Buffering depends on the concentration of the weak acid and its CB. The more weak acid present the more it can neutralize by dissociation of the acid. The more CB present, the more H+ can be neutralized.

Front 5

What is the intracellular buffer? What is the blood buffer system?

Back 5

1. organic phosphate buffer system
2. Bicarbonate/CO2 buffer system

Front 6

what is the barcarb/CO2 buffer system reaction?

Back 6

CO2(gas)↔CO2(dissolved)+H20↔H2CO3↔H+HCO3-

Front 7

HH equation for CO2/Bicarb buffer system

Back 7

pH=6.10+log [HCO3-]/[CO2] dissolved

Front 8

Why is the bicarb buffer system considered an open system?

Back 8

body responds to changes in CO2 and HC03. While the pka is 6.10 and the pH is 7.4 in the body, the bicarb buffer is still effective because of the RATIO of HCO3 to CO2, which determines the pH. pH=pka+log[CB/HA]

Front 9

Lungs control ______ & kidneys control _________

Back 9

1. CO2
HCO3 (bicarbonate)

Front 10

Acidemia

Back 10

blood pH lower than 7.35

Front 11

Respiratory Acidosis

Back 11

1. Acidosis due to increased PCO2

Front 12

Respiratory Acidosis imbalances and compensation

Back 12

decreased lung function, too much CO2, so don't breath hard enough. Kidneys compensate by increasing HCO3-

Front 13

Respiratory acidosis causes

Back 13

asthma, bronchitis, obesity, sedatives/anesthesia (too much CO2 so don't breath hard enough)

Front 14

Metabolic Acidosis definition

Back 14

acidosis due to decrease in HCO3 (increased H concentration)

Front 15

Metabolic Acidosis Causes

Back 15

Renal failure, methanol poisoning, diabetic ketoacidosis

Front 16

Metabolic Acidosis Compensation

Back 16

HCO3 goes down, then PCO2 will go down (rapid breathing/blowing off CO2)

Front 17

Alkalemia

Back 17

blood pH greater than 7.45

Front 18

Alkalosis

Back 18

process tending to raise pH

Front 19

Respiratory Alkalosis

Back 19

Alkalosis due to decreased PCO2 - hyperventalation (reduction of extracellular PCO2)

Front 20

Respiratory Alkalosis Causes

Back 20

Anxiety, pain, high altitude, mechanical hyperventilation (breath harder)

Front 21

Respiratory alkalosis compensations

Back 21

PCO2 decreases - thus the kidney tries to decrease HCO3- through urine excretion

Front 22

Metabolic Alkalosis definition

Back 22

alkalosis due to increased HCO3 (hypoventalation occurs to increase the PCO2).

Lungs slow breathing to increase PCO2. Can occur due to overdose of antacids - they take way all the H+

Front 23

Metabolic Alkalosis Causes

Back 23

too many antacids, acute alkali adminstration, vometing, gastric aspirations, diuretics

Front 24

Mixed acid-base disorders

Back 24

pt presents with lung disease (respiratory acidosis) and on diuretics (metabolic alkalosis) and may present with normal pH.