Learn / FMK
Every FMK condition
299 diseases, deficiencies, toxicities and drug mechanisms harvested from every FMK deck — the ones sprinkled through a single bullet as much as the ones with their own slide. Pick what you're given and what you have to name, or let it cycle; distractors come from the same category so you have to discriminate (hypoketotic vs. ketotic hypoglycemia, which GSD, which urea-cycle enzyme…). Every answer shows the whole card with the lecture and slide.
Toxin/Drug · FMK 02.2
5-Fluorouracil (5-FU) - thymidylate synthase inhibitor Acquired / not inherited
Defect / target: Thymidylate synthase (TS), inhibited by F-dUMP
Mechanism: Cells convert 5-FU to F-dUMP, which binds TS very tightly as a competitive inhibitor, so dUMP cannot be converted to dTMP and no dTTP or DNA is made.
↑ Accumulates: dUMP· ↓ Deficient: dTMP, dTTP, DNA synthesis
Presentation: Chemotherapy (colorectal and other cancers); adverse: myelosuppression, mucositis
5-FU -> F-dUMP -> blocks TS -> no dTMP -> no DNA
Learn the mechanism: Pyrimidine synthesis (& thymidylate) →
FMK 02.2 Nucleic Acid Structure; FMK 08.1 Nucleic Acid Metabolism · slide 02.2: 23; 08.1: 24, 29