ULTRA LONG HESI A2 ORIGINAL LONG SCENARIO REVISION
QUESTIONS
*Q1 LONG CHEM - Respiratory Alkalosis Buffer*
A 20-year-old nursing student is assigned to a 68-year-old COPD patient with chronic $CO2$
retention baseline $CO2$ 55 mmHg. Today patient gets anxiety attack, hyperventilates 32/min
for 45 min. ABG: pH 7.58, $PCO2$ 22 mmHg, $HCO3-$ 23. Buffer equation $CO2 + H2O \
leftrightarrow H2CO3 \leftrightarrow H+ + HCO3-$. Instructor asks direction of shift per Le
Chatelier when $CO2$ blown off and renal compensation in 48h.
A) Shift left, $H+$ decreases, pH rises, respiratory alkalosis, kidneys will excrete $HCO3-$
B) Shift right, pH falls
C) No shift
D) $HCO3-$ rises to 40
*Answer: A* - Hyperventilation removes $CO2$, equilibrium pulls left to make more $CO2$,
consuming $H+$, pH up. Chronic compensation: kidneys excrete bicarb.
*Q2 LONG CHEM - IV Precipitation Calcium Phosphate*
Night RN mixes TPN with Calcium gluconate 4.6 mEq and Potassium phosphate 15 mmol same
bag. Senior warns about $Ca3(PO4)2$ precipitation $Ksp 2.0x10^{-29}$. Concentrations $
[Ca2+]=5x10^{-3}M$, $[PO4^{3-}]=9x10^{-3}M$. $Q = ^{3}^{2} = 1.0x10^{-11}$. Q vs Ksp?
A) Q 1e-11 >> Ksp 2e-29, precipitates, microemboli risk, fatal, must separate lines, use filter
B) Safe, Q < Ksp
C) Only if heated
D) Shake and safe
*Answer: A*
*Q3 LONG CHEM - Hypertonic Saline Osmosis*
Neuro ICU patient cerebral edema needs 3% NaCl 1026 mOsm/L vs normal saline 0.9% 308
mOsm/L isotonic. RBC placed in 3% saline, what happens to RBC and brain cells and why this
helps intracranial pressure?
A) Water leaves RBC and brain cells into vessels by osmosis, cells crenate, water pulled from
brain tissue into blood, lowers ICP
B) Water enters cells, swells, worsens edema
C) No change
D) RBC lyses
*Answer: A*
*Q4 LONG CHEM - Redox Catalase Wound Cleaning*
Nurse cleans wound with $H2O2$, it bubbles $2H2O2 -> 2H2O + O2$. Blood contains catalase
enzyme. Oxidation state O in $H2O2$ is -1, in $O2$ is 0, in $H2O$ is -2. Type of redox?
, A) Disproportionation: same molecule oxidized (-1 to 0) and reduced (-1 to -2)
B) Only oxidation
C) Only reduction
D) Not redox
*Answer: A*
*Q5 LONG CHEM - Solubility and pH*
Patient with kidney stone calcium oxalate. Urine pH 5.0 acidic. Oxalate solubility increases in
acidic? $CaC2O4$ Ksp. In acidic pH, $C2O4^{2-}$ protonates to $HC2O4-$, lowers
$C2O4^{2-}$, shifts dissolution right, more soluble. But patient also has low citrate. Citrate binds
calcium. What advice?
A) Alkalinize urine to pH 6.5-7, increase citrate, increase fluid to increase solubility and prevent
precipitation
B) Acidify urine more
C) No effect of pH
D) Only calcium matters
*Answer: A*
*Q6 LONG BIO - Mitosis vs Meiosis Tumor vs Gamete*
Skin wound repair mitosis: 1 diploid 46 -> 2 diploid 46 identical. Ovary meiosis: 1 diploid 46 -> 4
haploid 23 different. Tumor grows via unchecked mitosis bypassing G1 checkpoint p53. If
nondisjunction in meiosis I, homologous chromosomes fail to separate, gamete gets 24
chromosomes, fertilized by normal 23 sperm gives?
A) 47 trisomy
B) 46 normal
C) 45 monosomy
D) 92 tetraploid
*Answer: A*
*Q7 LONG BIO - Enzyme pH Lactase vs Pepsin*
Lactase optimum pH 6.0 in small intestine brush border. Pepsin optimum pH 2.0 in stomach
activated from pepsinogen by HCl. Patient on high dose PPI omeprazole, stomach pH rises to
5.5. What happens to pepsin activity and lactase activity and protein vs lactose digestion?
A) Pepsin inactive denatured at pH 5.5, protein digestion decreased in stomach, lactase still
active in intestine pH 6, lactose digestion normal there
B) Both increase
C) Lactase inactive
D) Both denatured
*Answer: A*
*Q8 LONG BIO - DNA Replication Chemo Mechanism*
Woman 35 breast cancer HER2+ on 5-Fluorouracil blocks thymidylate synthase, dUMP to
dTMP, so dTTP missing. S phase needs A-T pairing 2 H-bonds, G-C 3 H-bonds. Cancer cells
spend more time in S phase than muscle cells G0 resting. What happens?
QUESTIONS
*Q1 LONG CHEM - Respiratory Alkalosis Buffer*
A 20-year-old nursing student is assigned to a 68-year-old COPD patient with chronic $CO2$
retention baseline $CO2$ 55 mmHg. Today patient gets anxiety attack, hyperventilates 32/min
for 45 min. ABG: pH 7.58, $PCO2$ 22 mmHg, $HCO3-$ 23. Buffer equation $CO2 + H2O \
leftrightarrow H2CO3 \leftrightarrow H+ + HCO3-$. Instructor asks direction of shift per Le
Chatelier when $CO2$ blown off and renal compensation in 48h.
A) Shift left, $H+$ decreases, pH rises, respiratory alkalosis, kidneys will excrete $HCO3-$
B) Shift right, pH falls
C) No shift
D) $HCO3-$ rises to 40
*Answer: A* - Hyperventilation removes $CO2$, equilibrium pulls left to make more $CO2$,
consuming $H+$, pH up. Chronic compensation: kidneys excrete bicarb.
*Q2 LONG CHEM - IV Precipitation Calcium Phosphate*
Night RN mixes TPN with Calcium gluconate 4.6 mEq and Potassium phosphate 15 mmol same
bag. Senior warns about $Ca3(PO4)2$ precipitation $Ksp 2.0x10^{-29}$. Concentrations $
[Ca2+]=5x10^{-3}M$, $[PO4^{3-}]=9x10^{-3}M$. $Q = ^{3}^{2} = 1.0x10^{-11}$. Q vs Ksp?
A) Q 1e-11 >> Ksp 2e-29, precipitates, microemboli risk, fatal, must separate lines, use filter
B) Safe, Q < Ksp
C) Only if heated
D) Shake and safe
*Answer: A*
*Q3 LONG CHEM - Hypertonic Saline Osmosis*
Neuro ICU patient cerebral edema needs 3% NaCl 1026 mOsm/L vs normal saline 0.9% 308
mOsm/L isotonic. RBC placed in 3% saline, what happens to RBC and brain cells and why this
helps intracranial pressure?
A) Water leaves RBC and brain cells into vessels by osmosis, cells crenate, water pulled from
brain tissue into blood, lowers ICP
B) Water enters cells, swells, worsens edema
C) No change
D) RBC lyses
*Answer: A*
*Q4 LONG CHEM - Redox Catalase Wound Cleaning*
Nurse cleans wound with $H2O2$, it bubbles $2H2O2 -> 2H2O + O2$. Blood contains catalase
enzyme. Oxidation state O in $H2O2$ is -1, in $O2$ is 0, in $H2O$ is -2. Type of redox?
, A) Disproportionation: same molecule oxidized (-1 to 0) and reduced (-1 to -2)
B) Only oxidation
C) Only reduction
D) Not redox
*Answer: A*
*Q5 LONG CHEM - Solubility and pH*
Patient with kidney stone calcium oxalate. Urine pH 5.0 acidic. Oxalate solubility increases in
acidic? $CaC2O4$ Ksp. In acidic pH, $C2O4^{2-}$ protonates to $HC2O4-$, lowers
$C2O4^{2-}$, shifts dissolution right, more soluble. But patient also has low citrate. Citrate binds
calcium. What advice?
A) Alkalinize urine to pH 6.5-7, increase citrate, increase fluid to increase solubility and prevent
precipitation
B) Acidify urine more
C) No effect of pH
D) Only calcium matters
*Answer: A*
*Q6 LONG BIO - Mitosis vs Meiosis Tumor vs Gamete*
Skin wound repair mitosis: 1 diploid 46 -> 2 diploid 46 identical. Ovary meiosis: 1 diploid 46 -> 4
haploid 23 different. Tumor grows via unchecked mitosis bypassing G1 checkpoint p53. If
nondisjunction in meiosis I, homologous chromosomes fail to separate, gamete gets 24
chromosomes, fertilized by normal 23 sperm gives?
A) 47 trisomy
B) 46 normal
C) 45 monosomy
D) 92 tetraploid
*Answer: A*
*Q7 LONG BIO - Enzyme pH Lactase vs Pepsin*
Lactase optimum pH 6.0 in small intestine brush border. Pepsin optimum pH 2.0 in stomach
activated from pepsinogen by HCl. Patient on high dose PPI omeprazole, stomach pH rises to
5.5. What happens to pepsin activity and lactase activity and protein vs lactose digestion?
A) Pepsin inactive denatured at pH 5.5, protein digestion decreased in stomach, lactase still
active in intestine pH 6, lactose digestion normal there
B) Both increase
C) Lactase inactive
D) Both denatured
*Answer: A*
*Q8 LONG BIO - DNA Replication Chemo Mechanism*
Woman 35 breast cancer HER2+ on 5-Fluorouracil blocks thymidylate synthase, dUMP to
dTMP, so dTTP missing. S phase needs A-T pairing 2 H-bonds, G-C 3 H-bonds. Cancer cells
spend more time in S phase than muscle cells G0 resting. What happens?
