Biochem Block 1: Water, Acids, Bases And Buffers (Bondarenko)

Front 1

Obese people have _______ % of body water than thin people

Back 1

less

Front 2

60% of total water body is found in the __________________ fluid.

Back 2

intracellular

Front 3

Why can a nonpolar substance like salt dissolve in a polar substance like water?

Back 3

hydration shells formed by water dissolve the anions and cations of salts

Front 4

Which has more of an effect on osmosis? Glucose or sodium?

Back 4

Sodium is an electrolyte--it has more osmotic power

Front 5

How does the sodium potassium pump work? How much of a neuron's energy does this pump use?

Back 5

3 Na out/2 K in. It uses 2/3 of neuronal energy expenditure

Front 6

Sodium is mainly found in the intracellular or extracellular compartments?

Back 6

extracellular (3 sodium are pumped out)

Front 7

potassium is found mainly in the intracellular or extracellular compartment?

Back 7

potassium is found in the intracellular (2 potassium are pumped in)

Front 8

Cl- is mainly found in the intracellular or extracellular compartment?

Back 8

Extracellular (Cl- gets pumped out with Na...think NaCl [salt])

Front 9

Hydrogen phosphate ion (HPO4 2-) is mainly found in the intracellular or extracellular compartment?

Back 9

Intracellular

Front 10

Which is more useful? Molarity or molality? Why?

Back 10

Molality (mol/kg) because it's a measure that doesn't rely on volume, which may change with temperature

Front 11

Water flows from ______ osmolarity to ______ osmolarity. why?

Back 11

low to high. Osmolarity is the measure of the concentration of solute in water, so low osmolarity means high water content. Water will flow to the compartment that needs it the most

Front 12

What is the osmotic pressure?

Back 12

the pressure that stops the movement of water from low osmolarity to high osmolarity. Measure of the strength of osmosis gradient

Front 13

A high osmolarity compartment has a __________ osmotic pressure. Why?

Back 13

high osmotic pressure. It takes a lot of pressure to stop water from entering this compartment

Front 14

Blood contains a lot of (negatively or positively) charged proteins and electrolytes

Back 14

negatively (think Cl-, HCO3-)

Front 15

When you have high blood sugar, what happens to the water content of cells?

Back 15

Water moves out of cells into the high osmolarity of the blood. Blood + interstitial fluid comprise the extracellular fluid

Front 16

An injury to the ________ can cause a lack of thirst

Back 16

hypothalamus

Front 17

When someone has a high level of glucose and ketone bodies in their blood, this causes water to leave the cells (intracellular dehydration) and causing more water to be excreted into the urine than normal. This process is called

Back 17

osmotic diuresis

Front 18

When diabetic patients have a high blood sugar, this causes osmotic diuresis. Osmotic diuresis causes the cells to become ___________. When this occurs in the brain, pt can go into a ______.

Back 18

dehydrated. coma

Front 19

Hypotonic hydration is caused by ______________ and results in ______________.

Back 19

excessive water ingestion or renal insufficiency...results in HYPONATREMIA (dilution of sodium in ECF)

Front 20

What is the range of normal blood pH?

Back 20

7.37 to 7.43

Front 21

Alkalosis of the blood is when the pH is...

Back 21

above 7.43

Front 22

Acidosis of the blood is when pH is...

Back 22

below 7.37

Front 23

What is the major metabolic source of acid in the body?

Back 23

CO2.
co2 + h2o = h2co3 (carbonic acid)

Front 24

What are the 4 major sources of acid (and the resulting hydrogen ions from the acid's dissociation) in the body?

Back 24

1. CO2 metabolites, mainly from krebs cycle
2. Catabolism of phosphorous containing compounds produces phosphoric acid (H3PO4)
3. Lactic acid from glycolysis
4. Ketones from fatty acid oxidation

Front 25

When a diabetic person does not take enough insulin, ketone bodies are produced because

Back 25

blood sugar will be high but cells will not be getting any glucose. thus the body thinks it is starving and will oxidize fatty acids for energy, producing ketone bodies

Front 26

What are the 2 ketone bodies?

Back 26

1. acetoacetic acid
2. beta-hydroxybutyric acid

Front 27

When a diabetic person produces ketones in their bodies, what happens?

Back 27

Ketoacidosis.
ketones are acids. when they dissociate, blood pH is lowered.

Front 28

Short term regulation (minutes) of blood pH is done by _______. Mid-term regulation (minutes) is done by _____. Long term regulation of blood pH (hours to days) is done by ________.

Back 28

short - buffers
mid - respiration center in brain, removing CO2 through expiration
long - renal system, removing H+ ions through urination

Front 29

Normal intracellular pH ranges from (note, this is different than blood pH) __________

Back 29

7.1 to 7.4

Front 30

What are the 4 major buffer systems in the body?

Back 30

1. bicarbonate-carbonic acid in ECF
2. Hemoglobin buffer system at RBCs
3. phosphate buffer system in all cells
4. ammonium and phosphate ion buffer system in kidney

Front 31

Carbonic acid has a pKa of 3.8. That means this acid is _________________ at the body's pH of 7.4.

Back 31

completely dissociated. pKa: pH at which half of this compound exists at dissociated form

Front 32

If pH falls (blood becomes more acidic), breathing gets __________. Why?

Back 32

much faster because you expire more CO2. Then you will have less CO2 available to become H2CO3

Front 33

when blood pH rises (more basic), your breathing becomes _________. why?

Back 33

slower. with slow breathing, less CO2 is expired. less CO2 expired means more CO2 is available in the body to become H2CO3.

Front 34

What enzyme converts water and CO2 to carbonic acid?

Back 34

carbonic anhydrase

Front 35

Lab results for someone with metabolic acidosis

Back 35

1. low pH
2. High [H+]
3. low pCO2 (more is being expired than normal)
4. low HCO3- (it's being bound to H+ to get rid of free H+ ions)

Front 36

Lab results for uncompensated respiratory alkalosis? Difference between metabolic acidosis

Back 36

When you increase your respiration rate despite no problem with pH, you have a low concentration of protons, high pH, low pCO2, and low HCO3-. Same as metabolic acidosis except high pH because it is uncompensated

Front 37

Respiratory acidosis

Back 37

Shallow breaths/diffculty breathing decreases CO2 expiration. Leads to accumulation of CO2, producing more carbonic acid, which dissociates and produces elevated H+, making blood acidic.

Front 38

Bicarbonate buffering system regulates

Back 38

blood pH

Front 39

When carbonic anhydrase acts in red blood cells to create carbonic acid, carbonic acid dissociates into bicarbonate and H+. H+ has 2 fates in the RBC. What are they? What is the fate of the bicarbonate?

Back 39

1. It will preferentially bind to hemoglobin.
2. It will bind to phosphate.

Bicarbonate will be pumped out of the cell and Cl- will be pumped into the cell to keep the cell neutral.

Front 40

Which amino acid on hemoglobin accepts protons in the hemoglobin buffering system?

Back 40

histidine

Front 41

describe how O2 gets to tissues

Back 41

CO2 is released from red blood cells at lungs. Carbonic acid formation requires HCO3 + H+. Concentration of protons in red blood cells goes down so more protons released from hemoglobin. Protons regulate binding affinity of Hb for oxygen. When we have high CO2, there will be more carbonic acid, more protons released, more proton binding to Hb, and Hb releases more O2. In the lungs, the rxn goes in reverse. CO2 is formed, proton is released from Hb. In tissue, releases O2 because the excessive formation of protons due to high CO2. Bicarb system linked to delivery of O2 to tissues.

Front 42

What is the major buffer system intracellularly?

Back 42

phosphate buffer system. H2PO4 > HPO4 2- + +H+

Front 43

If a cell becomes too acidic, how are protons transported?

Back 43

H+ is transported out of the cell in exchange for Na+.

Front 44

If a cell becomes too basic, how is bicarbonate transported?

Back 44

bicarbonate is transported out of the cell in exchange for Cl-

Front 45

what is the minimal urinary pH?

Back 45

5

Front 46

Acid secretion includes

Back 46

phosphate and ammonium ions, uric acid, dicarboxylic and tricarboxylic acids

Front 47

Excreted phosphate always equals

Back 47

ingested phosphate

Front 48

What is the major contributor to buffering URINARY pH?

Back 48

Ammonium.
nh3 (ammonia) + H > NH4 (ammonium)

Front 49

Ammonia is produced from

Back 49

amino acid metabolism

Front 50

What kind of stomach cells secrete HCl?

Back 50

parietal

Front 51

Bicarbonate is secreted from _______cells and the intestinal lining ___________ stomach contents.

Back 51

pancreatic; neutralize

Front 52

Describe the steps of metabolic alkalosis through vomiting.

Back 52

1. Excess H+ is lost through vomiting.
2. To replenish H+, H2CO3 dissociates in the stomach, replenishing H+. But the excess HCO3 produced from this dissociation raises HCO3 levels in the blood, which is basic. This increases blood pH.
3. To compensate, shallow breaths are taken to spare CO2 and thus decrease pH to normal ranges.

Front 53

Describe lab results for metabolic acidosis and the compensatory mechanism

Back 53

1. low [H+]
2. low blood pH
3. high [HCO3]
4. high pCO2 because breathing is slower, compensatory

Front 54

ASA has ______________ acid, which is converted to _____________ in the body

Back 54

acetylsalicylic acid; salicylic acid