What structures formed by bile salts transport fatty acids, monoglycerides, cholesterol, and fat-soluble vitamins to the brush border?
Micelles
Angular cheilitis and corneal vascularization are findings seen in deficiency of which vitamin?
Vitamin B2 (riboflavin)
Allopurinol decreases uric acid production by inhibiting which enzyme?
Xanthine oxidase
Name the two exclusively ketogenic amino acids.
Leucine and lysine
Overnight fasting produces severe hypoglycemia, low ketones, and elevated medium-chain acylcarnitines in an infant.
MCAD deficiency
Which major HDL apolipoprotein activates LCAT?
ApoA-I
A patient with autoimmune destruction of gastric parietal cells develops progressive numbness and gait instability. Which vitamin becomes deficient due to loss of intrinsic factor?
Vitamin B12
A cancer drug decreases both purine synthesis and dTMP synthesis by preventing regeneration of tetrahydrofolate. Name the drug.
Methotrexate
Unphosphorylated Rb inhibits which transcription factor?
E2F
Hyperammonemia, low BUN, and elevated urinary orotic acid in a male infant suggest which enzyme deficiency?
OTC deficiency
A monoclonal antibody prevents degradation of hepatic LDL receptors. What protein does it inhibit?
PCSK9
A patient has macrocytic anemia, glossitis, and elevated homocysteine, but methylmalonic acid is normal. Which vitamin is deficient?
Folate (B9)
A patient taking medication for alcohol use disorder develops flushing, nausea, vomiting, and hypotension after drinking.
Disulfiram
Which particle recognizes the N-terminal ER signal sequence of a newly translated protein?
Signal recognition particle (SRP)
A boy develops self-mutilation, dystonia, developmental delay, and hyperuricemia. Which enzyme is deficient?
HGPRT
Tremor, psychiatric changes, liver disease, and Kayser-Fleischer rings indicate what diagnosis?
Wilson disease
Vitamin B12 bound to intrinsic factor is absorbed primarily at what location?
Terminal ileum
A Parkinson patient receives levodopa with a drug that inhibits peripheral DOPA decarboxylase but does not cross the BBB.
Carbidopa
Fluoroquinolones inhibit which bacterial topoisomerases?
DNA gyrase/topoisomerase II and topoisomerase IV
β-oxidation of an odd-chain fatty acid ultimately generates acetyl-CoA plus which three-carbon molecule?
Propionyl-CoA
An infant develops failure to thrive and steatorrhea with extremely low cholesterol and triglycerides and absent chylomicrons, VLDL, and LDL.
Abetalipoproteinemia
A patient develops poor wound healing, impaired taste, alopecia, and periorificial dermatitis. What is deficient?
Zinc
A patient with salicylate toxicity has decreased PCO₂ and decreased HCO₃⁻ with a normal pH. What mixed acid-base disorder is present?
Respiratory alkalosis + anion-gap metabolic acidosis
What conserved sequence is located at the 3′ terminus of tRNA?
CCA
What is the inheritance of Hunters Syndrome?
X-linked