Banco Uworld 11/25

Apuntes

• Products of Eukaryotic RNA Polymerases Eukaryotic cells have three main RNA polymerases: - RNA polymerase I synthesizes rRNA - RNA polymerase II produces mRNA - RNA polymerase III generates tRNA • Mushroom Toxins and Clinical Manifestations Amatoxins in mushrooms like Amanita phalloides cause most mushroom fatalities. After ingestion, they are absorbed via the GI tract, transported to the liver, and concentrated by OATP and NTCP transporters. They inhibit RNA polymerase II, halting mRNA synthesis and inducing apoptosis, affecting rapidly renewing tissues such as GI and kidneys. Symptoms appear 6–24 hours post-ingestion, including abdominal pain, vomiting, diarrhea with blood and mucus, progressing to hepatic and renal failure. Urine α-amanitin testing aids diagnosis. • Antibiotic Resistance in Mycoplasma A novel antimicrobial inhibits bacterial glycosyltransferase, causing bacteria to become spherical, stop growth, and lyse. Resistance is assessed via zones of inhibition. Mycoplasma hominis, lacking a cell wall, is resistant to cell wall synthesis inhibitors like penicillins, but susceptible to ribosomal-targeting antibiotics such as macrolides and tetracyclines. ...