IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What is normal body pH? - (answer)7.35-7.45
What is normal pressure of carbon dioxide in the body? - (answer)35-45 mmHg
What is the normal level of bicarbonate in the body? - (answer)22-26 mEq/L
What does Mass action describe? - (answer)the effect of respiratory disorders and associated changes in
carbon dioxide on bicarb in the body
According to mass action, what happens when PCO2 changes in increments of 10 mmHg? - (answer)If
carbon dioxide raises by 10 mmHg, bicarb will increase by 1 mEq/L. If it decreases by ten, then bicarb
will decrease by two units
What is the normal value of the anion gap? - (answer)12 +/- 4
What is the anion gap? - (answer)the charge difference that exists based on the amount of Na, Cl, and
bicarb in the body
Why is the concentration of H+ tightly regulated within the body? - (answer)because H+ ions are very
reactive and can interfere with the structure and function of proteins if their concentration is left
unchecked
What is the difference between the degree of regulation of Na concentration in the body vs H+? -
(answer)H+ is regulated with much tighter control than most other body substances because it is so
highly reactive
What is the Henderson-Hasselbach equation? - (answer)Ph= pka+ log [HCO3-]/ 0.03 PCO2
What is pKa, as occurs in the Henderson Hasselbach equation? - (answer)it is an acid dissociation
constant
,IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What fraction is pH proportional to? - (answer)bicarb/carbon dioxide; or in other words, base divided by
acid
Changes in which two variables can be responsible for a shift in body pH? - (answer)in either bicarb or
carbon dioxide
What two factors determine the efficiency of a buffer? - (answer)its pKa and cocnentration
What is the role of a buffer's pKa? - (answer)it will be most effective at buffering acids near that pKa
Why is bicarbonate the most efficient buffer in the body? - (answer)because it is present in such high
concentration
What forms of regulation of bicarbonate allow it to be the most efficient buffer? - (answer)the fact that
it is both directly regulated by the kidneys and indirectly regulated by the lungs
what happens when bicarbonate binds acid? - (answer)it forms carbonic acid, which dissociates in to
carbon dioxide and water
What are the three main buffers found in the blood? - (answer)bicarbonate, hemoglobin,
phosphate/proteins
How much of the blood's buffering capacity occurs due to bicarbonate? - (answer)50%
How much of the blood's buffering capacity occurs due to hemoglobin? - (answer)35%
How much of the blood's buffering capacity occurs due to phosphate or other proteins? - (answer)15%
,IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What is the most important non-bicarbonate buffer in the blood? - (answer)hemoglobin
What aspect of bone allows it to act as a buffer? - (answer)H+ ions can displace the surface cations of
bone, thereby binding up the acid and preventing it from causing problems
How effective is bone as a buffer? - (answer)it takes a long time to have its effect, sometimes up to 4
hours
In which situation is bone a more effective buffer? - (answer)in chronic acidosis
What portion of the buffering is accomplished by bone in cases of chronic acidosis? - (answer)40%
Is bicarbonate an intracellular or extracellular buffer? - (answer)extracellular, since it is found at very
low concentrations within ells
What is the main intracellular buffer? - (answer)proteins
After proteins, what is the next best intracellular buffer? - (answer)phosphate
What kind of buffering occurs in cases of metabolic acidosis? - (answer)all bicarbonate in the body binds
to acid in order to buffer it. The bone and cells also play a role in buffering
What causes metabolic acidosis? - (answer)conditions like diarrhea, which cause bicarbonate to be lost
and causes the pH to decrease
During metabolic acidosis, is extracellular or intracellular buffering more active? - (answer)most of the
buffering occurs within cells
What is the role of bicarbonate in buffering respiratory acidosis? - (answer)it does not play a large role
because bicarbonate would regenerate carbonic acid if it tried to buffer it
, IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What is the role of red blood cells in buffering respiratory acidosis? - (answer)the hemoglobin within
these cells binds protons and accomplishes 35% of the buffering
What is the primary mechanism of buffering in respiratory acidosis? - (answer)mostly intracellular, with
only about 3% occurring extracellularly
What occurs in transcellular exchange in cases of acidosis caused by diabetes or COPD? - (answer)the
increased concentration of protons creates a concentration gradient that causes influx into cells. The
increase in positive charge within the cells causes K+ efflux, resulting in hyperkalemia
Which ion participates in transcellular exchange alongside H+? - (answer)potassium
What is the result of hyperkalemia resulting from transcellular exchange in cases of acidosis? -
(answer)it can result in arrhythmias and muscle weakness
What occurs in transcellular ion exchange during alkalosis? - (answer)K+ enters cells, as H+ leaves in
order to maintain electroneutrality. This raises the external pH
Would vomiting and hyperventilation cause acidosis or alkalosis? - (answer)alkalosis
What two variables can induce transcellualr ion exchange? - (answer)changes in the concentration of
either H+ or K+
What occurs in transcellular ion exchange when there is hyperkalemia? - (answer)K+ enters cells along
its concentration gradient, causing H+ to efflux and potentially modifying acid/base balance
What is a major cause of hyperkalemia, which could contribute to problems in acid/base balance via
transcellular exchange? - (answer)acute renal failure
What is normal body pH? - (answer)7.35-7.45
What is normal pressure of carbon dioxide in the body? - (answer)35-45 mmHg
What is the normal level of bicarbonate in the body? - (answer)22-26 mEq/L
What does Mass action describe? - (answer)the effect of respiratory disorders and associated changes in
carbon dioxide on bicarb in the body
According to mass action, what happens when PCO2 changes in increments of 10 mmHg? - (answer)If
carbon dioxide raises by 10 mmHg, bicarb will increase by 1 mEq/L. If it decreases by ten, then bicarb
will decrease by two units
What is the normal value of the anion gap? - (answer)12 +/- 4
What is the anion gap? - (answer)the charge difference that exists based on the amount of Na, Cl, and
bicarb in the body
Why is the concentration of H+ tightly regulated within the body? - (answer)because H+ ions are very
reactive and can interfere with the structure and function of proteins if their concentration is left
unchecked
What is the difference between the degree of regulation of Na concentration in the body vs H+? -
(answer)H+ is regulated with much tighter control than most other body substances because it is so
highly reactive
What is the Henderson-Hasselbach equation? - (answer)Ph= pka+ log [HCO3-]/ 0.03 PCO2
What is pKa, as occurs in the Henderson Hasselbach equation? - (answer)it is an acid dissociation
constant
,IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What fraction is pH proportional to? - (answer)bicarb/carbon dioxide; or in other words, base divided by
acid
Changes in which two variables can be responsible for a shift in body pH? - (answer)in either bicarb or
carbon dioxide
What two factors determine the efficiency of a buffer? - (answer)its pKa and cocnentration
What is the role of a buffer's pKa? - (answer)it will be most effective at buffering acids near that pKa
Why is bicarbonate the most efficient buffer in the body? - (answer)because it is present in such high
concentration
What forms of regulation of bicarbonate allow it to be the most efficient buffer? - (answer)the fact that
it is both directly regulated by the kidneys and indirectly regulated by the lungs
what happens when bicarbonate binds acid? - (answer)it forms carbonic acid, which dissociates in to
carbon dioxide and water
What are the three main buffers found in the blood? - (answer)bicarbonate, hemoglobin,
phosphate/proteins
How much of the blood's buffering capacity occurs due to bicarbonate? - (answer)50%
How much of the blood's buffering capacity occurs due to hemoglobin? - (answer)35%
How much of the blood's buffering capacity occurs due to phosphate or other proteins? - (answer)15%
,IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What is the most important non-bicarbonate buffer in the blood? - (answer)hemoglobin
What aspect of bone allows it to act as a buffer? - (answer)H+ ions can displace the surface cations of
bone, thereby binding up the acid and preventing it from causing problems
How effective is bone as a buffer? - (answer)it takes a long time to have its effect, sometimes up to 4
hours
In which situation is bone a more effective buffer? - (answer)in chronic acidosis
What portion of the buffering is accomplished by bone in cases of chronic acidosis? - (answer)40%
Is bicarbonate an intracellular or extracellular buffer? - (answer)extracellular, since it is found at very
low concentrations within ells
What is the main intracellular buffer? - (answer)proteins
After proteins, what is the next best intracellular buffer? - (answer)phosphate
What kind of buffering occurs in cases of metabolic acidosis? - (answer)all bicarbonate in the body binds
to acid in order to buffer it. The bone and cells also play a role in buffering
What causes metabolic acidosis? - (answer)conditions like diarrhea, which cause bicarbonate to be lost
and causes the pH to decrease
During metabolic acidosis, is extracellular or intracellular buffering more active? - (answer)most of the
buffering occurs within cells
What is the role of bicarbonate in buffering respiratory acidosis? - (answer)it does not play a large role
because bicarbonate would regenerate carbonic acid if it tried to buffer it
, IBSS 1540 EXAM 3 LECTURE 6 AND 7 TRAKA. EXAM 2025 QUESTIONS AND ANSWERS
What is the role of red blood cells in buffering respiratory acidosis? - (answer)the hemoglobin within
these cells binds protons and accomplishes 35% of the buffering
What is the primary mechanism of buffering in respiratory acidosis? - (answer)mostly intracellular, with
only about 3% occurring extracellularly
What occurs in transcellular exchange in cases of acidosis caused by diabetes or COPD? - (answer)the
increased concentration of protons creates a concentration gradient that causes influx into cells. The
increase in positive charge within the cells causes K+ efflux, resulting in hyperkalemia
Which ion participates in transcellular exchange alongside H+? - (answer)potassium
What is the result of hyperkalemia resulting from transcellular exchange in cases of acidosis? -
(answer)it can result in arrhythmias and muscle weakness
What occurs in transcellular ion exchange during alkalosis? - (answer)K+ enters cells, as H+ leaves in
order to maintain electroneutrality. This raises the external pH
Would vomiting and hyperventilation cause acidosis or alkalosis? - (answer)alkalosis
What two variables can induce transcellualr ion exchange? - (answer)changes in the concentration of
either H+ or K+
What occurs in transcellular ion exchange when there is hyperkalemia? - (answer)K+ enters cells along
its concentration gradient, causing H+ to efflux and potentially modifying acid/base balance
What is a major cause of hyperkalemia, which could contribute to problems in acid/base balance via
transcellular exchange? - (answer)acute renal failure
