NBME BIOCHEMISTRY SHELF EXAM (2026)
QUESTIONS AND ANSWERS
What neurotransmitter stimulates release of epinephrine from adrenal medulla? - ANSWER-
acetylcholine
What is a metabolite if epinephrine that suggests epi-secreting carcinoma? What is another assoc
symptom? - ANSWER-metanephrine; assoc with HBP
What does acetazolamide (carbonic anhydrase ib) treat? - ANSWER-glaucoma, epilepsy, altitude
sickness, congestive heart failure
can cause dehydration
Sickle cell anemia is due to... - ANSWER-pt mutation of Glu -> val
What is a major neurotransmitter amino acid? - ANSWER-Glu
HA protein of influenza binds to - ANSWER-cytokine receptors
What is a reducing-sugar test? - ANSWER-Tests for aldo-keto sugars
What is omeprazole? - ANSWER-proton pump ib
Name some GAG's. - ANSWER-heparin sulfate, chondroitin sulfate,
What type of reaction is glucuronidation? - ANSWER-oxidation
In Marfan's syndrome, what part of fibrillin's protein structure is affected? - ANSWER-primary
structure
What are the symptoms of Huntington's disease? - ANSWER-anxiety, uncontrollable mvmts,
slurring of speech, difficulty focusing or concentrating; caused by triple repeat expansion
What is Chediak-Higashi syndrome? - ANSWER-phagocyte deficiency ->
hypergammaglobulinemia, significant neutropenia,
In exposure to carbon monoxide or cyanide, which way does the ox sat curve shift? - ANSWER-
to the L; increased affinity at low pO_2
What is pralidoxime chloride? - ANSWER-reactivate acetylcholinesterase
Wernicke encephalopathy - ANSWER-inadequate thiamine; confusion, ophthalmoplagia
(nystagmus)
What is the function of lactase? - ANSWER-beta(1->4) galactosidase; cleaves Gal from Glu
How is fructose absorbed? - ANSWER-via sodium-independent transporter
, What sugar enzymes are found on the intestinal brush border? - ANSWER-sucrase, lactase,
maltase, isomaltase
Orlistat - ANSWER-ib pancreatic and gastric lipase; leads to reduced fat digestion
What is fiber? - ANSWER-glucose beta(1->4) glucose bonded sugar; body does not have beta(1-
4) endoglucosidase
enterokinase - ANSWER-activates trypsinogen; trypsin activates chymotrypsin, procolipase,
procarboxypeptidase, and proelastase
arsenic - ANSWER-pyruvate dehydrogenase ib; smell of garlic
Which GLUT is insulin-dependent? - ANSWER-GLUT4; found in muscle & adipose
What is the role of F2,6BP? - ANSWER-role player for insulin; increases glycolysis for FA synth
and glycogen synthesis
What is significant about glucokinase? - ANSWER-K_m is above fasting concentration, V_max
is very high
What promotes lactate buildup? - ANSWER-^ NADH/NAD+
Where does lactate build up? - ANSWER-eyes, testes, RBC's
What is the rate-limiting step of glycolysis? - ANSWER-PFK, allosterically activated by F2,6BP
Def in pyr kinase leads to... - ANSWER-2,3BPG, G6P elevation due to ^ PEP
What steroid can be used to treat beta-blocker overdose? - ANSWER-glucagon
Which form of aldolase is liver-specific? - ANSWER-B
triose phosphate isomerase - ANSWER-G3P <-> DHAP; DHAP - component of glycerol
phosphate shuttle
What TCA step makes GTP? - ANSWER-succinate thiokinase
What TCA step makes FADH? - ANSWER-succinate dehydrogenase
What is the only membrane-bound enzyme in TCA? - ANSWER-succinate dehydrogenase
What characterizes succinate? - ANSWER-dicarboxylic acid
pyruvate carboxylase - ANSWER-pyr -> OAA; requires biotin
Rotenone - ANSWER-inhibits complex I of ETC
antimycin - ANSWER-ib complex II, succinate dehydrogenase
Which ETC complex contains heme? - ANSWER-cytochrome oxidase
QUESTIONS AND ANSWERS
What neurotransmitter stimulates release of epinephrine from adrenal medulla? - ANSWER-
acetylcholine
What is a metabolite if epinephrine that suggests epi-secreting carcinoma? What is another assoc
symptom? - ANSWER-metanephrine; assoc with HBP
What does acetazolamide (carbonic anhydrase ib) treat? - ANSWER-glaucoma, epilepsy, altitude
sickness, congestive heart failure
can cause dehydration
Sickle cell anemia is due to... - ANSWER-pt mutation of Glu -> val
What is a major neurotransmitter amino acid? - ANSWER-Glu
HA protein of influenza binds to - ANSWER-cytokine receptors
What is a reducing-sugar test? - ANSWER-Tests for aldo-keto sugars
What is omeprazole? - ANSWER-proton pump ib
Name some GAG's. - ANSWER-heparin sulfate, chondroitin sulfate,
What type of reaction is glucuronidation? - ANSWER-oxidation
In Marfan's syndrome, what part of fibrillin's protein structure is affected? - ANSWER-primary
structure
What are the symptoms of Huntington's disease? - ANSWER-anxiety, uncontrollable mvmts,
slurring of speech, difficulty focusing or concentrating; caused by triple repeat expansion
What is Chediak-Higashi syndrome? - ANSWER-phagocyte deficiency ->
hypergammaglobulinemia, significant neutropenia,
In exposure to carbon monoxide or cyanide, which way does the ox sat curve shift? - ANSWER-
to the L; increased affinity at low pO_2
What is pralidoxime chloride? - ANSWER-reactivate acetylcholinesterase
Wernicke encephalopathy - ANSWER-inadequate thiamine; confusion, ophthalmoplagia
(nystagmus)
What is the function of lactase? - ANSWER-beta(1->4) galactosidase; cleaves Gal from Glu
How is fructose absorbed? - ANSWER-via sodium-independent transporter
, What sugar enzymes are found on the intestinal brush border? - ANSWER-sucrase, lactase,
maltase, isomaltase
Orlistat - ANSWER-ib pancreatic and gastric lipase; leads to reduced fat digestion
What is fiber? - ANSWER-glucose beta(1->4) glucose bonded sugar; body does not have beta(1-
4) endoglucosidase
enterokinase - ANSWER-activates trypsinogen; trypsin activates chymotrypsin, procolipase,
procarboxypeptidase, and proelastase
arsenic - ANSWER-pyruvate dehydrogenase ib; smell of garlic
Which GLUT is insulin-dependent? - ANSWER-GLUT4; found in muscle & adipose
What is the role of F2,6BP? - ANSWER-role player for insulin; increases glycolysis for FA synth
and glycogen synthesis
What is significant about glucokinase? - ANSWER-K_m is above fasting concentration, V_max
is very high
What promotes lactate buildup? - ANSWER-^ NADH/NAD+
Where does lactate build up? - ANSWER-eyes, testes, RBC's
What is the rate-limiting step of glycolysis? - ANSWER-PFK, allosterically activated by F2,6BP
Def in pyr kinase leads to... - ANSWER-2,3BPG, G6P elevation due to ^ PEP
What steroid can be used to treat beta-blocker overdose? - ANSWER-glucagon
Which form of aldolase is liver-specific? - ANSWER-B
triose phosphate isomerase - ANSWER-G3P <-> DHAP; DHAP - component of glycerol
phosphate shuttle
What TCA step makes GTP? - ANSWER-succinate thiokinase
What TCA step makes FADH? - ANSWER-succinate dehydrogenase
What is the only membrane-bound enzyme in TCA? - ANSWER-succinate dehydrogenase
What characterizes succinate? - ANSWER-dicarboxylic acid
pyruvate carboxylase - ANSWER-pyr -> OAA; requires biotin
Rotenone - ANSWER-inhibits complex I of ETC
antimycin - ANSWER-ib complex II, succinate dehydrogenase
Which ETC complex contains heme? - ANSWER-cytochrome oxidase
