Sylvia Exam Ultimate Guide: High-Yield, Ultra-Detailed Biochemistry, Genetics, Metabolism, Enzymes, Vitamins, Amino Acids, and Inborn Errors of Metabolism Verified Questions Provided with A+ Graded Rationales LATEST UPDATED 2026

Sylvia Exam Ultimate Guide: High-Yield, Ultra-Detailed Biochemistry, Genetics, Metabolism, Enzymes, Vitamins, Amino Acids, and Inborn Errors of Metabolism Verified Questions Provided with A+ Graded Rationales LATEST UPDATED 2026 what is the most common extracellular buffer? bicarbonate what is the isoelectric point? the ph at which there is no charge what is the rate limiting enzyme in glycolysis? phosphfructokinase-1 (PFK-1) what is the rate limiting enzyme in gluconeogenesis? fructose-1,6-bisphosphatase what is the rate limiting enzyme in the HMP shunt? glucose-6-phosphate dehydrogenase (g6pd) what is the rate limiting enzyme in glycogenesis? glycogen synthase where does glycogenesis occur? cytoplasm of liver and muscle what is the rate limiting enzyme in glycogenolysis? glycogen phosphorylase (in cytoplasm of liver and muscle) what is the rate limiting enzyme in FA synthesis? acetyl-CoA carboxylase (ACC) what is the rate lim enzyme in beta-oxidation? carnitine acetyltransferase-1 what is the rate lim enzyme in cholesterol synthesis? HMG CoA reductase what is the rate lim enzyme in ketogenesis? HMG CoA synthase what is the rate limiting enzyme in purine synthesis? glutamine- phosphoriboryl pyrophosphate (PRPP) aminotransferase rate lim enzyme in pyrimidine synthesis? carbamoyl phosphate synthetase-2 (CPS-2) rate lim enzyme in TCA cycle? isocitrate dehydrogenase what is the rate lim enzyme in the urea cycle? carbamoyl phosphate synthetase-1 (CPS-1) rate lim enzyme in heme synthesis? delta-ALA synthase what are the catabolic pathways that create energy? (occur in mitochondria) acetyl-coA production, beta-oxidation, citric acid cycle, ketogenesis, oxidative phosphorylation (ETC) what are the anabolic pathways that store energy? (occur in cytoplasm) FA synthesis glycolysis hmp shunt translation what are the anabolic + catabolic pathways? (occur in cytoplasm and mitochondria) "HUG" H- heme synthesis U- urea cycle G- gluconeogenesis what does an isomerase do? creates an isomer (same chemical make-up but different structure) what does an epimerase do? creates an epimer, which differs around one chiral carbon (same chemical make-up and structure) what does a mutase do? relocates a functional group within a molecule (intrachain). Ex: (moving one Carbon from one side chain to another) what does a transferase do? relocates a functional group from one molecule to another (interchain) what does a kinase do? adds phosphate group to substrate using ATP what does a phosphorylase do? adds inorganic phosphate to substrate, no ATP used what does a carboxylase do? transfers CO2 groups with the help of biotin what does a synthase do? consumes 2 substrates what does a synthetase do? consumes 2 substrates, uses ATP what does a phosphatase do? removes phosphate from a substrate wh