EXAM FLASHCARDS (BUS VERSION) 🔴 PDC (these are BIG) Q: What does PDC do? A: Pyruvate (3C) → acetyl-CoA (2C) + CO₂ + NADH ⸻ Q: PDC Step 1 A: Decarboxylation of pyruvate to an aldehyde (TPP, E1) ⸻ Q: PDC Step 2 A: Oxidation of aldehyde to carboxylic acid (lipoamide, E2) ⸻ Q: PDC Step 3 A: Formation of acetyl-CoA (transfer to CoA-SH) ⸻ Q: PDC Step 4 A: Reoxidation of lipoamide (FAD → FADH₂) ⸻ Q: PDC Step 5 A: Regeneration of FAD via NAD⁺ → NADH ⸻ Q: PDC inhibitors A: ATP, NADH, acetyl-CoA, fatty acids ⸻ Q: PDC activators A: AMP, CoA, NAD⁺, Ca²⁺ ⸻ 🟠 CAC CORE Q: CAC net products (per acetyl-CoA) A: 2 CO₂, 3 NADH, 1 FADH₂, 1 GTP ⸻ Q: CAC intermediates (order) A: Citrate → Isocitrate → α-KG → Succinyl-CoA → Succinate → Fumarate → Malate → OAA ⸻ Q: CAC enzymes that release CO₂ A: Isocitrate dehydrogenase, α-KG dehydrogenase ⸻ Q: Rate-limiting CAC enzyme A: Isocitrate dehydrogenase ⸻ Q: CAC regulatory enzymes A: Citrate synthase, Isocitrate DH, α-KG DH ⸻ Q: CAC activated by A: ADP, Ca²⁺ ⸻ Q: CAC inhibited by A: ATP, NADH, citrate, succinyl-CoA ⸻ Q: CAC enzyme in ETC A: Succinate dehydrogenase (inner mitochondrial membrane) ⸻ 🟡 NET vs INTERMEDIATE (this prevents mistakes) Q: Is oxaloacetate a net CAC product? A: No — regenerated ⸻ Q: Is citrate a net CAC product? A: No — intermediate ⸻ Q: Why does CAC stop without O₂? A: NADH builds up → NAD⁺ depleted ⸻ 🔵 CARBON LABELING (glycolysis) Q: Glucose C1 & C6 → pyruvate? A: C3 (methyl carbon) ⸻ Q: Glucose C2 & C5 → pyruvate? A: C2 (central carbon) ⸻ Q: Glucose C3 & C4 → pyruvate? A: C1 (carboxylate) ⸻ 🟢 GLYCOGEN (VERY LIGHT) Q: Glycogen phosphorylase product A: Glucose-1-phosphate ⸻ Q: Glycogenesis vs gluconeogenesis A: Glycogenesis = glycogen synthesis Gluconeogenesis = glucose synthesis ⸻ 🟣 PPP (recognition only) Q: PPP purpose A: NADPH + ribose-5-phosphate ⸻ Q: PPP regulation A: NADPH inhibits G6P dehydrogenase
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