ACS Biochemistry Final Exam 2024: Complete 200 Questions with Detailed Answers, Exams of Biochemistry

Download ACS Biochemistry Final Exam 2024: Complete 200 Questions with Detailed Answers and more Exams Biochemistry in PDF only on Docsity! 1 | P a g e ACS BIOCHEMISTRY FINAL EXAM 2024 ACTUAL EXAM COMPLETE 200 QUESTIONS WITH DETAILED VERIFIED ANSWERS (100% CORRECT ANSWERS) ALREADY GRADED A+ What is the D configuration of a sugar in a Fisher projection? - CORRECT ANSWER >>>>chyrolcarbon furthest from the carboxyl group hydroxyl on right What is the L configuration of a sugar in a Fisher projection? - CORRECT ANSWER >>>>hydroxyl on left What is the difference between glycogen and amylopectin? - CORRECT ANSWER >>>>glycogen- has branches about every 10 residues (more highly branched) 2 | P a g e amylopectin- has branches about every 25 What is amylose made up of? - CORRECT ANSWER >>>>glucose What makes up starch? - CORRECT ANSWER >>>>amylose amlyopectin What is a glycosidic bond? - CORRECT ANSWER >>>>links two monosaccharides together at points 1 and 4 What is the difference between an alpha(1-4) and beta(1-4) linkage? - CORRECT ANSWER >>>>alpha: when the oxygen is pointed down in a glycosidic bond beta: when the oxygen is pointed up in a glycosidic bond 5 | P a g e Why type of amino acid is present in the plasma membrane among the fatty acid tails? - CORRECT ANSWER >>>>hydrophobic/nonpolar What is passive transport (simple diffusion)? - CORRECT ANSWER >>>>no energy required no protein required move from high concentration to low concentration water, gases, ethanol (small nonpolar) can pass through What is facilitated diffusion? - CORRECT ANSWER >>>>requires protein no energy required molecules are two large to go through on their own 6 | P a g e What is active transport? - CORRECT ANSWER >>>>energy is required moves from low to high concentration How many carbon atoms do most fatty acids have? - CORRECT ANSWER >>>>even number What bond holds nucleotides together? - CORRECT ANSWER >>>>phosphodiester bond What base pairing exists in nucleic acids? How many hydrogen bonds between them? - CORRECT ANSWER >>>>G--C (3 hydrogen bonds) A--T (2 hydrogen bonds) What is the first amino acid always placed in a protein? - CORRECT ANSWER >>>>methionine (Met) start codon 7 | P a g e What 3 things make up a nucleotide? - CORRECT ANSWER >>>>nitrogen base phosphate group pento-sugar (ribose or deoxyribose) What are the 3 main differences between DNA and RNA? - CORRECT ANSWER >>>>RNA single strand DNA is double stranded RNA has uracil DNA has thiamine RNA has ribose DNA has deoxyribose What part of the structure makes DNA such a stable molecule? - CORRECT ANSWER >>>>very polar sugar phosphate backbound the bases are stacked in the interior that are nonpolar 10 | P a g e What is an allosteric enzyme? - CORRECT ANSWER >>>>there are two bonding sites (active site and another) What do enzymes do? - CORRECT ANSWER >>>>catalyze a reaction What enzyme forms a bond between four molecules? - CORRECT ANSWER >>>>ligase How do enzymes work? - CORRECT ANSWER >>>>lower the activation energy to catalyze the reaction What is enzyme cooperativity? - CORRECT ANSWER >>>>when one subunit binds oxygen, it changes shape and makes it more likely for the other subunit What is the difference between competitive and noncompetitive inhibitors? - CORRECT 11 | P a g e ANSWER >>>>competitive inhibitor: substrate and inhibitor compete to bind with the active site noncompetitive inhibitor: inhibitor binds to allosteric site instead of active site but enzyme can't also bind What is oxidation and reduction? - CORRECT ANSWER >>>>reduction: add hydrogen to result in a higher chemical potential oxidation: When you have a hydrolysis of bonds in food, what does that do? - CORRECT ANSWER >>>>releases energy What reaction breaks bonds within cells? - CORRECT ANSWER >>>>hydrolysis 12 | P a g e When a reaction breaks bonds within cells, does this reaction require or release energy? - CORRECT ANSWER >>>>releases energy How does the reaction that breaks bonds within cells relate to delta G? - CORRECT ANSWER >>>>energy is used to build the bonds the delta G becomes negative when energy is released What factors affect enzyme activity? - CORRECT ANSWER >>>>pH heat What process results in the anabolism of glucose? - CORRECT ANSWER >>>>hydrolysis of the anhydride bonds provide energy for anabolism What is the main function of NADH within cellular respiration? - CORRECT ANSWER 15 | P a g e Henderson-Hasselbach Equation - CORRECT ANSWER >>>>pH = pKa + log ([A-] / [HA]) FMOC Chemical Synthesis - CORRECT ANSWER >>>>Used in synthesis of a growing amino acid chain to a polystyrene bead. FMOC is used as a protecting group on the N-terminus. Salting Out (Purification) - CORRECT ANSWER >>>>Changes soluble protein to solid precipitate. Protein precipitates when the charges on the protein match the charges in the solution. Size-Exclusion Chromatography - CORRECT ANSWER >>>>Separates sample based on size with smaller molecules eluting later. Ion-Exchange Chromatography - CORRECT ANSWER >>>>Separates sample based on 16 | P a g e charge. CM attracts +, DEAE attracts -. May have repulsion effect on like charges. Salt or acid used to remove stuck proteins. Hydrophobic/Reverse Phase Chromatography - CORRECT ANSWER >>>>Beads are coated with a carbon chain. Hydrophobic proteins stick better. Elute with non-H-bonding solvent (acetonitrile). Affinity Chromatography - CORRECT ANSWER >>>>Attach a ligand that binds a protein to a bead. Elute with harsh chemicals or similar ligand. SDS-PAGE - CORRECT ANSWER >>>>Uses SDS. Gel is made from cross-linked polyacrylamide. Separates based off of mass with smaller molecules moving faster. Visualized with Coomassie blue. 17 | P a g e SDS - CORRECT ANSWER >>>>Sodium dodecyl sulfate. Unfolds proteins and gives them uniform negative charge. Isoelectric Focusing - CORRECT ANSWER >>>>Variation of gel electrophoresis where protein charge matters. Involves electrodes and pH gradient. Protein stops at their pI when neutral. FDNB (1-fluoro-2,3-dinitrobenzene) - CORRECT ANSWER >>>>FDNB reacts with the N-terminus of the protein to produce a 2,4-dinitrophenol derivative that labels the first residue. Can repeat hydrolysis to determine sequential amino acids. DTT (dithiothreitol) - CORRECT ANSWER >>>>Reduces disulfide bonds. 20 | P a g e Parallel ß-sheet - CORRECT ANSWER >>>>Same sheet directions (C & N-termini line up). Has angled H-bonds. ß-turns - CORRECT ANSWER >>>>Tight u-turns with specific phi-psi angles. Must have gly at position 3. Proline may also be at ß-turn because it can have a cis-omega angle. Loops - CORRECT ANSWER >>>>Not highly structured. Not necessary highly flexible, but can occasionally move. Very variable in sequence. Circular Dichroism - CORRECT ANSWER >>>>Uses UV light to measure 2° structure. Can be used to measure destabilization. Disulfide-bonds - CORRECT ANSWER >>>>Bonds between two -SH groups that form between 2° and 3° structure. 21 | P a g e ß-mercaptoethanol - CORRECT ANSWER >>>>Breaks disulfide bonds. α-keratin - CORRECT ANSWER >>>>formed from 2 α-helices twisted around each other. "Coiled coil". Cross-linked by disulfide bonds. Collagen - CORRECT ANSWER >>>>Repeating sequence of Gly-X-Pro. 3 stranded "coiled coil". Contains gly core. Myoglobin 4° Structure - CORRECT ANSWER >>>>Symmetric homodimer, Hemoglobin 4° Structure - CORRECT ANSWER >>>>Tetramer. Dimer of dimers. α2ß2 tetramer. α/ß Protein Folding - CORRECT ANSWER >>>>Less distinct areas of α and ß folding. 22 | P a g e α+ß Protein Folding - CORRECT ANSWER >>>>Two distinct areas of α and ß folding. Mechanism of Denaturants - CORRECT ANSWER >>>>Highly soluble, H-binding molecules. Stabilize protein backbone in water. Allows denatured state to be stabilized. Temperature Denaturation of Protein - CORRECT ANSWER >>>>Midpoint of reaction is Tm. Cooperative Protein Folding - CORRECT ANSWER >>>>Folding transition is sharp. More reversible. Folding Funnel - CORRECT ANSWER >>>>Shows 3D version of 2D energy states. Lowest energy is stable protein. Rough funnel is less cooperative. 25 | P a g e O2 Binding Event - CORRECT ANSWER >>>>O2 binds to T-state and changes the heme to R- state. Causes a 0.4Å movement of the iron. Hemoglobin Binding Curve - CORRECT ANSWER >>>>4 subunits present in hemoglobin that can be either T or R -state. Cooperative binding leads to a sigmoidal curve. Binding Cooperativity - CORRECT ANSWER >>>>When one subunit of hemoglobin changes from T to R-state the other sites are more likely to change to R-state as well. Leads to sigmoidal graph. Homotropic Regulation of Binding - CORRECT ANSWER >>>>Where a regulatory molecule is also the enzyme's substrate. Heterotropic Regulation of Binding - CORRECT ANSWER >>>>Where an allosteric regulator is present that is not the enzyme's substrate. 26 | P a g e Hill Plot - CORRECT ANSWER >>>>Turns sigmoid into straight lines. Slope = n (# of binding sites). Allows measurement of binding sites that are cooperative. pH and Binding Affinity (Bohr Affect) - CORRECT ANSWER >>>>As [H+] increases, Histidine group in hemoglobin becomes more protonated and protein shifts to T-state. O2 binding affinity decreases. CO2 binding in Hemoglobin - CORRECT ANSWER >>>>Forms carbonic acid that shifts hemoglobin to T-state. O2 binding affinity decreases. Used in the peripheral tissues. BPG (2,3-bisphosphoglycerate) - CORRECT ANSWER >>>>Greatly reduces hemoglobin's affinity for O2 by binding allosterically. Stabilizes T-state. Transfer of O2 can improve 27 | P a g e because increased delivery in tissues can outweigh decreased binding in the lungs. Michaelis-Menton Equation - CORRECT ANSWER >>>>V0 = (Vmax[S]) / (Km + [S]) Km in Michaelis-Menton - CORRECT ANSWER >>>>Km = [S] when V0 = 0.5(Vmax) Michaelis-Menton Graph - CORRECT ANSWER >>>> Lineweaver-Burke Graph - CORRECT ANSWER >>>>Slope = Km/Vmax Y-intercept = 1/Vmax X-intercept = - 1/Km Lineweaver-Burke Equation - CORRECT ANSWER >>>>Found by taking the reciprocal of the Michaelis-Menton Equation. 30 | P a g e Mutarotation - CORRECT ANSWER >>>>Conversion from α to ß forms of the sugar at the anomeric carbon. Anomeric Carbon - CORRECT ANSWER >>>>Carbon that is cyclized. Always the same as the aldo or keto carbon in the linear form. α vs. ß sugars - CORRECT ANSWER >>>>α form has -OR/OH group opposite from the -CH2OH group. ß form has -OR/OH group on the same side as the -CH2OH group. Starch - CORRECT ANSWER >>>>Found in plants. D-glucose polysaccharide. "Amylose chain". Unbranched. Has reducing and non- reducing end. Amylose Chain - CORRECT ANSWER >>>>Has α- 1,4-linkages that produce a coiled helix similar 31 | P a g e to an α-helix. Has a reducing and non-reducing end. Amylopectin - CORRECT ANSWER >>>>Has α- 1,4-linkages. Has periodic α-1,6-linkages that cause branching. Branched every 24-30 residues. Has reducing and non-reducing end. Reducing Sugar - CORRECT ANSWER >>>>Free aldehydes can reduce FeIII or CuIII. Aldehyde end is the "reducing" end. Glycogen - CORRECT ANSWER >>>>Found in animals. Branched every 8-12 residues and compact. Used as storage of saccharides in animals. Cellulose - CORRECT ANSWER >>>>Comes from plants. Poly D-glucose. Formed from ß-1,4- linkage. Form sheets due to equatorial -OH groups that H-bond with other chains. 32 | P a g e Chitin - CORRECT ANSWER >>>>Homopolymer of N-acetyl-ß-D-glucosamine. Have ß-1,4- linkages. Found in lobsters, squid beaks, beetle shells, etc. Glycoproteins - CORRECT ANSWER >>>>Carbohydrates attached to a protein. Common outside of the cell. Attached at Ser, Thr, or Asn residues. Membrane Translayer Flip-Flop - CORRECT ANSWER >>>>Typically slow, but can be sped up with Flippase, Floppase, or Scramblase. Membrance Fluidity - CORRECT ANSWER >>>>Membrane must be fluid. Cis fats increase fluidity, trans fats decrease fluidity. Type I Integral Membrane Protein - CORRECT ANSWER >>>>Membrane protein with C- terminus inside and N-terminus outside 35 | P a g e A-form DNA - CORRECT ANSWER >>>>Condensed form of DNA. Deeper major groove and shallower minor groove. B-form DNA - CORRECT ANSWER >>>>Watson- Crick model DNA. Deep, wide major groove. Z-form DNA - CORRECT ANSWER >>>>Left- handed helical form of DNA Inverted Repeat in DNA - CORRECT ANSWER >>>>Found in double-strands. TTAGCAC|GTGCTAA AATCGTG|CACGATT Forms a cruciform. Mirror Repeat in DNA/RNA - CORRECT ANSWER >>>>Found in single-strands. TTAGCAC|GTGCTAA Forms a hairpin 36 | P a g e DNA UV Absorbtion - CORRECT ANSWER >>>>Absorbs UV light at 260nm. Restriction Enzyme - CORRECT ANSWER >>>>Cuts DNA at specific restriction sites. DNA Base-paring - CORRECT ANSWER >>>>G-C base pairs have 3 H-bonds A-T base pairs have 2 H-bonds GPCR (G-protein coupled receptor) - CORRECT ANSWER >>>>α-helical integral membrane proteins. Is a αßɣ heterotrimer. ß-adrenergic receptor - CORRECT ANSWER >>>>Prototype for all GPCR's. Bind adrenaline/epinephrine to stimulate breakdown of glycogen. Step 1 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>Epinephrine binds to its specific receptor 37 | P a g e Step 2 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>Hormone complex causes GDP bound to α-subunit to be replaced by GTP, activating α-subunit Step 3 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>Activated α-subunit separates from ßɣ-complex and moves to adenylyl cyclase, activating it. Step 4 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>Adenylyl cyclase catalyzes the formation of cAMP from ATP Step 5 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>cAMP phosphorylates PKA, activating it Step 6 of Epinephrine Signal Transduction - CORRECT ANSWER >>>>Phosphorylated PKA 40 | P a g e NADH - CORRECT ANSWER >>>> FADH2 - CORRECT ANSWER >>>>Single-electron transfer NADPH - CORRECT ANSWER >>>> FMN - CORRECT ANSWER >>>>Single electron transfer. Step 1 of Glycolysis - CORRECT ANSWER >>>>Glucose --> Glucose 6-phosphate. Uses hexokinase enzyme. ATP --> ADP Step 2 of Glycolysis - CORRECT ANSWER >>>>Glucose 6-phosphate <--> Fructose 6- phosphate Uses phosphohexose isomerase enzyme. 41 | P a g e Step 3 of Glycolysis - CORRECT ANSWER >>>>Fructose 6-phosphate --> Fructose 1,6- bisphosphate Uses PFK-1 (phosphofructokinase-1) enzyme. ATP --> ADP First Committed Step of Glycolysis - CORRECT ANSWER >>>>Step 3 of Glycolysis. Fructose 6-Phosphate --> Fructose 1,6- bisphosphate. (PFK-1) Step 4 of Glycolysis - CORRECT ANSWER >>>>Fructose 1,6-bisphosphate <--> dihydroxyacetone + glyceraldehyde 3- phosphate. Uses aldolase enzyme. Step 5 of Glycolysis - CORRECT ANSWER >>>>Dihydroxyacetonephosphate <--> glyceraldehyde 3-phosphate Uses triose phosphate isomerase enzyme. 42 | P a g e Step 6 of Glycolysis - CORRECT ANSWER >>>>Glyceraldehyde 3-Phosphate + Pi <--> 1,3- biphosphoglycerate. Uses G3P dehydrogenase enzyme. NAD+ <--> NADH First Energy Yielding Step of Glycolysis - CORRECT ANSWER >>>>Step 6 of Glycolysis. G3P + Pi <--> 1,3-bisphosphoglycerate Step 7 of Glycolysis - CORRECT ANSWER >>>>1,3-bisphosphoglycerate + ADP <--> 3- phosphoglycerate + ATP Uses phosphoglycerate kinase enzyme. First ATP Yielding Step of Glycolysis - CORRECT ANSWER >>>>Step 7 of Glycolysis. 1,3-bisphosphoglycerate <--> 3- phosphoglycerate Step 8 of Glycolysis - CORRECT ANSWER >>>>3- phosphoglycerate <--> 2-phosphoglycerate 45 | P a g e TPP Cofactor - CORRECT ANSWER >>>>Common acetaldehyde carrier. Used in pyruvate decarboxylase, pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and transketolase Bypass Reactions in Gluconeogenesis - CORRECT ANSWER >>>>Steps 1,3, and 10 must be bypassed. Gluconeogenic Bypass of Step 10 - CORRECT ANSWER >>>>Bicarbonate + Pyruvate --> Oxaloacetate Pyruvate decarboxylate (biotin) ATP --> ADP Oxaloacetate --> PEP PEP carboxykinase GTP --> GDP + CO2 46 | P a g e Gluconeogenic Bypass of Step 3 - CORRECT ANSWER >>>>Fructose 1,6-bisphosphate + H2O --> Fructose 6-phosphate + Pi Uses FBPase-1 (coordinated with PFK-1) Gluconeogenic Bypass of Step 1 - CORRECT ANSWER >>>>Glucose 6-phosphate + H2O --> Glucose + Pi Uses glucose 6-phosphatase. Cost of Gluconeogenesis - CORRECT ANSWER >>>>4 ATP, 2 GTP, and 2 NADH Oxidative Pentose Phosphate Pathway - CORRECT ANSWER >>>>Uses glucose 6- phosphate to produce 2 NADPH and ribose 5- phosphate used for biosynthesis Non-Oxidative Pentose Phosphate Pathway - CORRECT ANSWER >>>>Regenerates glucose 6- phosphate from ribose 5-phosphate. Uses transketolase and transaldolase enzymes. 47 | P a g e Transketolase - CORRECT ANSWER >>>>Transfers a two-carbon keto group Transaldolase - CORRECT ANSWER >>>>Transfers a three-carbon aldo group Enzyme Km and Substrate Concentration - CORRECT ANSWER >>>>Most enzymes have a Km that is near the concentration of the substrate. Fructose 2,6-bisphosphate - CORRECT ANSWER >>>>Not a glycolytic intermediate. Interconverts between fructose 2,6- bisphosphate and fructose 6-phosphate using PFK-2 and FBPase-2 Regulation with fructose 2,6-bisphosphate - CORRECT ANSWER >>>>Activates PFK-1 encouraging glycolysis. Inhibits FBPase-1 discouraging gluconeogenesis 50 | P a g e Uses isocitrate dehydrogenase NAD(P)+ --> NAD(P)H + CO2 Step 4 of the Citric Acid Cycle - CORRECT ANSWER >>>>α-ketoglutarate --> succinyl-CoA Uses α-ketoglutarate dehydrogenase complex CoA + NAD+ --> NADH + CO2 Step 5 of the Citric Acid Cycle - CORRECT ANSWER >>>>Succinyl-CoA <--> Succinate Uses succinyl-CoA synthetase enzyme GDP + Pi <--> GTP + CoA Step 6 of the Citric Acid Cycle - CORRECT ANSWER >>>>Succinate <--> Fumarate Uses succinate dehydrogenase FAD <--> FADH2 Step 7 of the Citric Acid Cycle - CORRECT ANSWER >>>>Fumarate <--> L-Malate Uses fumarase enzyme 1) OH- 2) H+ --> 51 | P a g e Step 8 of the Citric Acid Cycle - CORRECT ANSWER >>>>L-Malate <--> Oxaloacetate Uses malate dehydrogenase enzyme NAD+ <--> NADH Net Energy Gain of the Citric Acid Cycle - CORRECT ANSWER >>>>3 NADH, FADH2, and GTP NADH Producing Steps of the Citric Acid Cycle - CORRECT ANSWER >>>>Steps 3, 4, and 8. Isocitrate --> α-ketoglutarate α-ketoglutarate --> Succinyl-CoA L-Malate --> Oxaloacetate FADH2 Producing Steps of the Citric Acid Cycle - CORRECT ANSWER >>>>Step 6 Succinate <--> Fumarate Using succinate dehydrogenase enzyme 52 | P a g e GTP/ATP Producing Steps of the Citric Acid Cycle - CORRECT ANSWER >>>>Step 5 Succinyl-CoA <--> Succinate Using succinyl-Coa synthetase CO2 Producing Steps of the Citric Acid Cycle - CORRECT ANSWER >>>>Steps 3 and 4 Isocitrate --> α-ketoglutarate α-ketoglutarate --> Succinyl-CoA Biotin Structure - CORRECT ANSWER >>>> Biotin Function - CORRECT ANSWER >>>>Prosthetic group that serves as a CO2 carrier to separate active sites on an enzyme Regulation of the Citric Acid Cycle - CORRECT ANSWER >>>>Regulation occurs at Steps 1, 2, 4, and 5. High energy molecules (ATP, Acetyl-CoA, NADH) inhibit while low-energy molecules (ADP, AMP, CoA, NAD+) activate these steps 55 | P a g e Step 4 of ß-oxidation - CORRECT ANSWER >>>>ß-ketoacyl-CoA (+ CoA) --> Fatty acyl-Coa (shorter) Uses thiolase enzyme ß-oxidation in plants - CORRECT ANSWER >>>>Electrons are passed directly to molecular oxygen releasing heat and H2O2 instead of the respiratory chain. ω-oxidation - CORRECT ANSWER >>>>Similar to ß-oxidation but occurs simultaneously on both ends of the molecule. α-oxidation - CORRECT ANSWER >>>>Form of oxidation of branched FA's. Produced propionyl-CoA that must be converted to succinyl-CoA for use in the CAC Ketone bodies - CORRECT ANSWER >>>>Consists of Acetoacetate, Acetone, and D- ß-hydroxybutryate. 56 | P a g e 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 - CORRECT ANSWER >>>>An inactive precursor of an enzyme, activated by various methods (acid hydrolysis, cleavage by another enzyme, etc.) PLP Structure - CORRECT ANSWER >>>> Amidotransferase - CORRECT ANSWER >>>>Uses 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 - CORRECT ANSWER >>>>L-glutamate is converted to L- glutamine via glutamine synthetase. ATP + NH4+ --> ADP + Pi 57 | P a g e L-glutamine can be converted back to L- glutamate in the liver. Glucose-Alanine Cycle - CORRECT ANSWER >>>>Pyruvate 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 - CORRECT ANSWER >>>>NH4+ --> Carbamoyl Phosphate Produced by carbamoyl phosphate synthetase I 2 ATP + HCO3 --> 2ADP + Pi Step 1 of the Urea Cycle - CORRECT ANSWER >>>>Ornithine (+ carbamoyl phosphate) --> citrulline Uses ornithine transcarbamoylase enzyme Only step to occur in the mitochondria 60 | P a g e pKa of Tyrosne R-group - CORRECT ANSWER >>>>10 FAD Structure - CORRECT ANSWER >>>> Q (Ubiquinone/Coenzyme Q) Structure - CORRECT ANSWER >>>> Q (Ubiquinone/Coenzyme Q) Function - CORRECT ANSWER >>>>Lipid soluble electron carrier. Carries 2 electrons with 2 H+. ETC (Electron Transport Chain) - CORRECT ANSWER >>>>Consists of 4 functional protein complexes. Complex I in the ETC - CORRECT ANSWER >>>>Accepts two electrons from NADH via an FMN cofactor. Transfers 4H+ to Pside and 2H+ to Q 61 | P a g e Complex II in the ETC - CORRECT ANSWER >>>>Succinate dehydrogenase. Accepts two electrons electrons from succinate via an FAD group. Q --> QH2 Complex III in the ETC - CORRECT ANSWER >>>>Transfers two electrons from QH2 to cytochrome c via the Q-cycle. Transfers 4H+ to Pside. Complex IV in the ETC - CORRECT ANSWER >>>>Transfers 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 - CORRECT ANSWER >>>>Consists of F1 and F0 domains F1 Domain of Mitochondrial ATP Synthase - CORRECT ANSWER >>>>Hexamer of 3 αß dimers. Catalyze ADP + Pi --> ATP via binding- change model 62 | P a g e F0 Domain of Mitochondrial ATP Synthase - CORRECT ANSWER >>>>Causes rotation of γ- subunit via a half channel and H+ gradient Malate-Aspartate Shuttle - CORRECT ANSWER >>>>Used 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) - CORRECT ANSWER >>>>Incorporates CO2 into ribulose 1,5- bisphosphate and cleaves the 6C intermediate into 2 3-phosphoglycerate. Stage 1 of the Calvin Cycle - CORRECT ANSWER >>>>3 ribulose 1-5-bisphosphate + 3 CO2 --> 6 3-phosphoglycerate. Catalyzed by rubisco 65 | P a g e Glycolate Cycle - CORRECT ANSWER >>>>Process of converting 2-phosphoglycerate to 3-phosphoglycerate in chloroplast, peroxisome, and mitochondria. C4 Plants - CORRECT ANSWER >>>>Fix 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 - CORRECT ANSWER >>>>Fix CO2 into PEP to form oxaloacetate (via PEP carboxykinase) that is converted to malate at night and stored until the day time. Malonyl-CoA - CORRECT ANSWER >>>>Formed from Acetyl-CoA and HCO3 via the Acetyl-CoA carboxylase (ACC). Serves as a regulator of FA catabolism and precursor in FA synthesis. 66 | P a g e ACC (acetyl-CoA carboxylase) Regulation - CORRECT ANSWER >>>>Inhibited by PKA in glucagon chain and activated by pjhosphatase in INSR chain. FAS (Fatty-acid Synthetase) - CORRECT ANSWER >>>>Catalyzes condensation, reduction, dehydration, and reduction of growing fatty acid chain. Requires activation by acetyl-CoA or malonyl-CoA Additional Cost of FAS in Eukaryotes - CORRECT ANSWER >>>>Acetyl-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 - CORRECT ANSWER >>>>3 ATP's per 2 carbon unit added. Phosphatidic Acid - CORRECT ANSWER >>>>Common precursor to TAGs and 67 | P a g e phospholipids. Consists of a glycerol 3- phosphate with two acyl groups that are attached via acyl transferases. TAGs (Triacylglycerols) - CORRECT ANSWER >>>>Made from phosphatidic acid by removing phosphate with phosphatase and adding an acyl group with acyl transferase. Cholesterol Synthesis - CORRECT ANSWER >>>>Synthesized from 15 acetyl-CoA through a number of intermediates. HMG-CoA Reductase - CORRECT ANSWER >>>>Enzyme that converts ß-hydroxy-ß-methyl glutaryl-CoA to mevalonate in cholesterol metabolism. Regulation of HMG-CoA Reductase - CORRECT ANSWER >>>>Inhibited by AMPK (AMP dependent kinase), glucagon, and oxysterol. Activated by insulin.