ACS BIOCHEMISTRY EXAM LATES UPDATED VERSION WITH CORRECT QUESTIONS AND ANSWERS GRADED A+

ACS BIOCHEMISTRY EXAM LATES UPDATED VERSION WITH CORRECT QUESTIONS AND ANSWERS GRADED A+ Ketone bodies - Answer️Consists of Acetoacetate, Acetone, and D-ß-hydroxybutryate. Formation begins from condensation of 2 acetyl-CoA -- Acetoacetyl-CoA (+ CoA) D-ß-hydroxybutryate can be broken into 2 acetyl-CoA and used as fuel. Zymogen - Answer️An inactive precursor of an enzyme, activated by various methods (acid hydrolysis, cleavage by another enzyme, etc.) PLP Structure - Answer️ Aminotransferase - Answer️Uses a PLP group to transfer amino group from an amino acid to α-ketoglutarate to form L-glutamate and an α-ketoglutarate. Ammonia (NH4+) Transportation - Answer️L-glutamate is converted to L-glutamine via glutamine synthetase. ATP + NH4+ -- ADP + Pi L-glutamine can be converted back to L-glutamate in the liver. Glucose-Alanine Cycle - Answer️Pyruvate can be converted into Alanine via alanine aminotransferase (PLP). Adds a NH4+ group from glutamate to pyruvate. Alanine can travel to the liver and be reconverted back into pyruvate needed for gluconeogenesis. Production of carbamoyl-phosphate - Answer️NH4+ -- Carbamoyl Phosphate Produced by carbamoyl phosphate synthetase I 2 ATP + HCO3 -- 2ADP + Pi Step 1 of the Urea Cycle - Answer️Ornithine (+ carbamoyl phosphate) -- citrulline Uses ornithine transcarbamoylase enzyme Only step to occur in the mitochondria Step 2 of the Urea Cycle - Answer️Citrulline -- Arginosuccinate Uses arginosuccinate synthetase 1) ATP -- ADP 2) Aspartate -- AMP Step 3 of the Urea Cycle - Answer️Arginosuccinate -- Argininine Uses arginosuccinase Produces fumarate byproduct Step 4 of the Urea Cycle - Answer️Arginine -- Ornithine Uses arginase enzyme H2O -- Urea N-acetylglutamate - Answer️Upregulates the production of carbamoyl phosphate and the urea cycle. Formed from acetyl-CoA and glutamate. PCR (Protein Chain Reaction) - Answer️Process by which DNA is replicated. Has melting step, annealing step, replication step. pKa of Arginine R-group - Answer️12.5 pKa of Aspartate R-group - Answer️3.9 pKa of Cysteine R-group - Answer️8 pKa of Glutamate R-group - Answer️4 pKa of Histidine R-group - Answer️6.1 pKa of Lysine R-group - Answer️10.5 pKa of Tyrosne R-group - Answer️10 FAD Structure - Answer️ Q (Ubiquinone/Coenzyme Q) Structure - Answer️ Q (Ubiquinone/Coenzyme Q) Function - Answer️Lipid soluble electron carrier. Carries 2 electrons with 2 H+. ETC (Electron Transport Chain) - Answer️Consists of 4 functional protein complexes. Complex I in the ETC - Answer️Accepts two electrons from NADH via an FMN cofactor. Transfers 4H+ to Pside and 2H+ to Q Complex II in the ETC - Answer️Succinate dehydrogenase. Accepts two electrons electrons from succinate via an FAD group. Q -- QH2 Complex III in the ETC - Answer️Transfers two electrons from QH2 to cytochrome c via the Q-cycle. Transfers 4H+ to Pside. Complex IV in the ETC - Answer️Transfers electrons from cytochrome c to O2. Four electrons are used to reduce on O2 into two H2O molecules. Transfers 4H+ to Pside Mitochondrial ATP Synthase - Answer️Consists of F1 and F0 domains F1 Domain of Mitochondrial ATP Synthase - Answer️Hexamer of 3 αß dimers. Catalyze ADP + Pi -- ATP via binding-change model F0 Domain of Mitochondrial ATP Synthase - Answer️Causes rotation of γ-subunit via a half channel and H+ gradient Malate-Aspartate Shuttle - Answer️Used to maintain gradient of NADH inside of the mitochondria. Involves transport of malate or aspartate; aspartate aminotransferase; and malate dehydrogenase. RuBisCo (Ribulose 1,5-bisphosphate carboxylase/oxygenase) - Answer️Incorporates CO2 into ribulose 1,5-bisphosphate and cleaves the 6C intermediate into 2 3-phosphoglycerate. Stage 1 of the Calvin Cycle - Answer️3 ribulose 1-5-bisphosphate + 3 CO2 -- 6 3-phosphoglycerate. Catalyzed by rubisco Mg2+ in Rubisco - Answer️Stabilizes negative charge in intermediate and held by Glu, Asp, and carbamoylated Lysine residue Rubisco Activase - Answer️Triggers removal of ribulose 1,5-bisphosphate or 2-carboxyaarabinitol 1-phosphate so Lys can be carbamoylated. 2-carboxyarabinitol 1-phosphate - Answer️inhibits carbamoylated rubisco. Synthesized in the dark and is broken down by rubisco activase or light. Stage 2 of the Calvin Cycle - Answer️3-phosphoglycerate -- glyceraldehyde 3-phosphate Requires ATP and NADPH Goes through 1,3-bisphosphoglycerate intermediate Stage 3 of the Calvin Cycle - Answer️Glyceraldehyde 3-phosphate -- Ribulose 1,5-bisphosphate Requires 3 ATP and uses transketolase (TPP). Only uses 8 of the 9 G3P's produced. One G3P is used to make starch/sucrose. Energy Consumption of the Calvin Cycle - Answer️9 ATP molecules and 6 NADPH molecules for every 3 CO2 molecules that are fixated. Pi-Triose Phosphate Anti-porter - Answer️Maintains Pi balance in cytosol/chloroplast due to G3P export to the cytosol. Also exports ATP and NADH to the cytosol. Oxygenase Activity in Rubisco - Answer️O2 competes with CO2 and reacts to form 2-phosphoglycerate Glycolate Cycle - Answer️Process of converting 2-phosphoglycerate to 3-phosphoglycerate in chloroplast, peroxisome, and mitochondria. C4 Plants - Answer️Fix CO2 into PEP to form oxaloacetate (via PEP carboxykinase) that is then converted to malate that carries CO2 to rubisco. Bypasses O2 binding. CAM plants - Answer️Fix CO2 into PEP to form oxaloacetate (via PEP carboxykinase) that is converted to malate at night and stored until the day time. Malonyl-CoA - Answer️Formed from Acetyl-CoA and HCO3 via the Acetyl-CoA carboxylase (ACC). Serves as a regulator of FA catabolism and precursor in FA synthesis. ACC (acetyl-CoA carboxylase) Regulation - Answer️Inhibited by PKA in glucagon chain and activated by pjhosphatase in INSR chain. FAS (Fatty-acid Synthetase) - Answer️Catalyzes condensation, reduction, dehydration, and reduction of growing fatty acid chain. Requires activation by acetyl-CoA or malonyl-CoA Additional Cost of FAS in Eukaryotes - Answer️Acetyl-CoA for lipid synthesis is made in mitochondria and must be transferred into the cytosol via citrate transporter. Costs 2 ATP. Cost of FAS in Eukaryotes - Answer️3 ATP's per 2 carbon unit added. Phosphatidic Acid - Answer️Common precursor to TAGs and phospholipids. Consists of a glycerol 3-phosphate with two acyl groups that are attached via acyl transferases. TAGs (Triacylglycerols) - Answer️Made from phosphatidic acid by removing phosphate with phosphatase and adding an acyl group with acyl transferase. Cholesterol Synthesis - Answer️Synthesized from 15 acetyl-CoA through a number of intermediates. HMG-CoA Reductase - Answer️Enzyme that converts ß-hydroxy-ß-methyl glutaryl-CoA to mevalonate in cholesterol metabolism. Regulation of HMG-CoA Reductase - Answer️Inhibited by AMPK (AMP dependent kinase), glucagon, and oxysterol. Activated by insulin. Ribonucleotide Reductase - Answer️Contains two types of allosteric regulatory sites for activity and specificity. Converts ribonucleotides to deoxyribonucleotides. Nitrogenase Complex - Answer️Uses ATP hydrolysis and ATP binding to overcome activation energy. Has a FeMo cofactor. Is an α2ß2 homodimer. Fixes N2 into NH4+ Anaerobic Ammonia Oxidation (Anammox) - Answer️Ability of some bacteria to oxidize NH4+ and NO2- into N2. "Short-circuits" the nitrogen cycle. Glutamine Synthetase Regulation in Nitrogen Metabolism - Answer️Catalyzes conversion of glutamate to glutamine. Inhibited by Gly, Ala, and endpoints of glutamine metabolism. Additive effectors.