carbohydrate and Energy metabolism
This enzyme catalyzes the rate-limiting step of glycolysis, converting fructose-6-phosphate to fructose-1,6-bisphosphate.
What is phosphofructokinase-1 (PFK-1)?
This enzyme catalyzes the rate-limiting step of fatty acid synthesis, producing malonyl-CoA from acetyl-CoA.
What is acetyl-CoA carboxylase (ACC)?
Deficiency of this enzyme decreases NADPH production in red blood cells, increasing susceptibility to oxidative hemolysis.
What is glucose-6-phosphate dehydrogenase (G6PD)?
This dimorphic fungus is associated with bird or bat droppings and can survive within macrophages.
What is Histoplasma capsulatum?
This antifungal class inhibits beta-1,3-D-glucan synthesis, disrupting the fungal cell wall.
What are echinocandins?
This vitamin-derived cofactor is required by pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, and its deficiency can cause lactic acidosis.
What is thiamine pyrophosphate (vitamin B1)
This apolipoprotein activates lipoprotein lipase, allowing triglycerides in chylomicrons and VLDL to be hydrolyzed.
What is ApoC-II?
A child develops intellectual disability, seizures, and a musty body odor due to impaired conversion of phenylalanine into tyrosine. This metabolic disorder is present.
What is phenylketonuria (PKU)?
A patient develops intense nocturnal itching with burrows between the fingers after close contact with an infected individual. This ectoparasite is responsible.
What is Sarcoptes scabiei?
This antiprotozoal drug is commonly used to treat Trichomonas vaginalis and Giardia infections through formation of toxic metabolites that damage microbial DNA.
What is metronidazole?
A child develops vomiting, hypoglycemia, and liver dysfunction after eating fruit. Deficiency of this enzyme causes hereditary fructose intolerance.
What is aldolase B?
During prolonged fasting, this organ produces ketone bodies but cannot utilize them because it lacks thiophorase.
What is the liver?
An infant develops hepatomegaly, fasting hypoglycemia, lactic acidosis, and hyperuricemia due to deficiency of glucose-6-phosphatase. This glycogen storage disease is present
What is von Gierke disease (glycogen storage disease type I)?
A patient with poorly controlled diabetes develops facial pain, black necrotic nasal tissue, and rapidly progressive sinus infection. This fungal infection is most likely.
What is rhinocerebral mucormycosis?
This antifungal binds ergosterol and forms membrane pores, causing fungal cell death, but is associated with nephrotoxicity.
What is amphotericin B?
A patient with pyruvate dehydrogenase deficiency develops lactic acidosis. This metabolic pathway converts excess pyruvate into lactate to regenerate NAD+ for continued glycolysis.
What is anaerobic glycolysis (lactate fermentation)?
A fasting infant develops hypoketotic hypoglycemia, lethargy, and dicarboxylic aciduria. Deficiency of this beta-oxidation enzyme is most likely.
What is medium-chain acyl-CoA dehydrogenase (MCAD)?
A child develops developmental regression, exaggerated startle response, and a cherry-red macula without hepatosplenomegaly. This lysosomal enzyme is deficient.
What is hexosaminidase A?
A patient develops fever, severe headache, and a rash involving the wrists, ankles, palms, and soles following a tick bite. This bacterial pathogen is most likely.
What is Rickettsia rickettsii?
Methotrexate inhibits this enzyme, decreasing tetrahydrofolate availability and impairing nucleotide synthesis.
What is dihydrofolate reductase (DHFR)?
A patient with cyanide poisoning develops severe lactic acidosis despite adequate oxygen delivery. This electron transport chain complex is directly inhibited.
What is complex IV (cytochrome c oxidase)?
A newborn develops severe hyperammonemia with elevated urinary orotic acid and decreased citrulline. This urea cycle enzyme is deficient.
What is ornithine transcarbamylase (OTC)?
A patient develops recurrent kidney stones, gout, and self-injurious behavior due to impaired purine salvage. This enzyme is deficient.
What is hypoxanthine-guanine phosphoribosyltransferase (HGPRT)?
A patient from rural Latin America develops dilated cardiomyopathy, arrhythmias, and megaesophagus years after infection by a triatomine bug. This protozoan is responsible.
What is Trypanosoma cruzi?
A patient receiving 5-fluorouracil is given leucovorin to enhance chemotherapy efficacy. This nucleotide synthesis enzyme is more effectively inhibited as a result.
What is thymidylate synthase?