Biochemistry exam
Biochemistry CHEM 3500Summer 2020Exam 4Name: ______________________________ Dr. Meades 36 possible pointsFor questions 1-36, choose the one best answer (1 point each). You may keep the exam questions. 1.) A non-redox step in oxidation of fatty acids utilizes _____, concurrently shortening the chain by _____ carbon atoms. A) NADH / 0B) CoA / 2C) H2O / 4D) FADH2 / 2E) H2O / 2F) CoA / 3G) FMN / 2 2.) Individuals with Andersen disease are unable to construct normal glycogen granules, instead forming the low water solubility molecules seen below, which precipitate in liver cells resulting in cirrhosis. Which enzyme is defective in these individuals? A) glycogen synthaseB) glycogen phosphorylaseC) debranching enzymeD) branching enzyme E) glycogeninF) phosphoglucose isomeraseG) phosphorylase kinase 3.) The ester shown to the right is derived directly from methanol and what biochemical molecule? (Look at it carefully!) A) citrateB) isocitrateC) succinateD) acetyl-CoAE) pyruvateF) oxaloacetateG) malate 4.) _____ transport mainly triacylglycerols in the blood from the liver to other cells. A) chylomicronsB) VLDLsC) LDLsD) HDLsE) albuminsF) insulinsG) midichlorians 5.) The enzyme in the reaction depicted below belongs to what class? (Think about this one carefully!) A) hydrolaseB) isomeraseC) lyaseD) transferaseE) ligaseF) kinase G) oxidoreductase 6.) What is the name of the enzyme whose mechanism is depicted in the previous question? A) enolase B) hexokinase C) aldolase D) pyruvate carboxylase E) aldolase F) RuBisCO G) ribose carboxylase 7.) The product formed in step 2 of the enzymatic reaction depicted above has become unstable primarily because _____. A) the phosphate negative charges are now closerB) it now contains exactly three double bondsC) both A & B D) it is now a β-keto acidE) it is a peroxideF) both D & EG) It is actually stable as an α-keto acid. 8.) The same enzyme can also utilize O2 in place of CO2 as the substrate by mistake. What makes the result of step 2 below unstable? A) the phosphate negative charges are now closerB) it now contains exactly three double bondsC) both A & B D) it is now a β-keto acidE) it is a peroxideF) both D & EG) It is actually stable as an α-keto acid. 9.) Which of the following is NOT involved in the synthesis of fatty acids? A) acetyl-CoAB) NADPHC) biotin D) malonyl-CoA E) ACPF) CO2G) All of the above ARE involved. 10.) Almost all of the nitrogen waste in the form of uric acid originates from _____. A) CO2B) inhaled N2C) glucoseD) purinesE) fructoseF) waterG) pyrimidines 11.) The ultimate electron donor in photosynthesis is _____. A) O2B) H2OC) NADP+D) NADPHE) CO2F) N2 G) photons of light 12.) Which of the following amino acids is (are) strictly ketogenic upon degradation? A) isoleucineB) leucineC) lysineD) valineE) tyrosineF) A & C onlyG) B & C only 13.) Partial oxidation of a 20:0 fatty acid could yield which of the following in addition to an acyl-CoA longer than 5 carbons? 14.) Complete oxidation of a 10:1Δ7 fatty acid yields which of the following? 15.) Complete oxidation of an 11:1Δ7 fatty acid yields which of the following in addition to propionyl-CoA (3:0)? A) 4 acetyl CoA + 3 FADH2 + 4 NADH + 4 H+B) 4 acetyl CoA + 4 FADH2 + 4 NADH + 4 H+ C) 5 acetyl CoA + 3 FADH2 + 4 NADH + 4 H+D) 5 acetyl CoA + 4 FADH2 + 5 NADH + 5 H+ E) 6 acetyl CoA + 5 FADH2 + 6 NADH + 6 H+F) 6 acetyl CoA + 5 FADH2 + 5 NADH + 5 H+ G) 6 acetyl CoA + 4 FADH2 + 5 NADH + 5 H+ 16.) Which labeled monosaccharides are NOT removed as glucose-1-phoshate during glycogen degradation? (choose all that apply) 17.) Which TWO labeled monosaccharides could be acted upon by the branching enzyme at this point in time? 18.) Which TWO labeled monosaccharides would be moved by the debranching enzyme during glycogen degradation? 19.) Which TWO labeled monosaccharides were added by glycogenin during glycogen synthesis? 20.) Which of the following requisite metal ions or metal ion clusters is matched with the appropriate enzyme or pathway for which it serves as a cofactor? A) Mn2+ - glycolysisB) Mg-Ca - photosynthesisC) Mo-Fe - RuBisCOD) Ti-Al - nitrogenase E) Co2+ - cholesterol synthesisF) Fe-Ni - amino acid synthesisG) none of the above 21.) The major site for the action of acyl-CoA synthetase is which of the following? A) inner mitochondrial membraneB) cytoplasmC) thylakoid membraneD) matrix E) outer mitochondrial membraneF) stromaG) chloroplastic intermembrane space 22.) In preparation for glycogen synthesis, the enzyme UDP-glucose pyrophosphorylase uses substrates containing _____ and _____ phosphates. A) 0, 4B) 1, 2C) 2, 0D) 1, 3E) 2, 3F) 3, 3G) 2, 4 23.) Conversion of glycogen to glucose for export by a muscle cell involves which of the following enzymes? A) phosphoglucose isomeraseB) glucose-1-phosphorylaseC) glycogen synthaseD) aldolase E) phosphoglycerate mutaseF) glucose-6-phosphataseG) none of the above 24.) In the synthesis of a single cholesterol molecule, _____ ATP’s are utilized directly and _____ methyl groups are removed. A) 3, 9B) 9, 4C) 10, 3D) 17, 4E) 18, 3F) 6, 6G) 36, 6 25.) Which of the following statements about β-oxidation of fatty acids is CORRECT? A) Not all fatty acids must be activated to acyl-CoAs before entering the pathway. B) Thiolytic cleavage releases acetyl-CoA and a shortened acyl-CoA in the final step of the cycle. C) Both dehydrogenation reactions produce a C=O double bond. D) Both dehydrogenation reactions use FAD as the electron acceptor. E) For an odd-length fatty acid containing a C=C double bond, the location of the C=C double bond alternates even/odd. F) For an even-length fatty acid containing a C=C double bond, the location of the C=C double bond alternates even/odd. G) The first oxidation step is favorable because it eliminates an unstable α-keto arrangement. 26.) The reactions catalyzed by acyl-CoA synthetase and DNA polymerase share what feature driving them forward energetically? A) loss of CO2B) oxidation of NADPHC) elimination of an α-keto acidD) elimination of a β-keto acid E) subsequent hydrolysis of pyrophosphate by pyrophosphataseF) hydrolysis of ATPG) all of the above 27.) The sources of the five nitrogen atoms of adenine in de novo synthesis can be described by which of the following? A) 2 from glycine, 2 from glutamate, 1 from aspartateB) 2 from glutamate, 2 from aspartate, 1 from glycine C) 3 from glycine, 2 from glutamateD) 1 from glycine, 1 from glutamate, 1 from aspartate, 2 from ammonia E) 3 from aspartate, 1 from glutamate, 1 from glycineF) 4 from aspartate, 1 from glutamate G) Adenine only has four nitrogen atoms, not five: 2 from glutamate, 1 from aspartate, 1 from glycine. 28.) The sources of the three nitrogen atoms of cytosine in de novo synthesis can be described by which of the following? A) 2 from aspartate, 1 from glutamateB) 1 from aspartate, 2 from glutamineC) all 3 from aspartate D) 1 from aspartate, 1 from glutamine, 1 from CO2E) 3 from aspartate, 1 from glutamate, 1 from glycine F) 1 from aspartate, 2 from ATPG) 2 from glutamate, 1 from glycine. 29.) _____ rounds of the Calvin cycle are required for the net production of a hexose sugar. A) 1B) 2C) 4D) 6E) 9F) 12G) 36 30.) What is the equivalent functional component or space in mitochondria to the chloroplastic outer membrane? A) mitochondrial outer membraneB) mitochondrial inner membraneC) mitochondrial intermembrane space D) matrixE) stromaF) thylakoid membraneG) none of the above 31.) During the linear flow of electrons through PS I and II, how many photons are needed per electron to complete the entire trip? A) 0B) 0.5C) 1D) 1.5E) 2F) 2.5G) 3 32.) During the Kok cycle of PS II, the cubane cluster of one Ca and four Mn ions harbors its largest total charge at what stage? A) S0B) S1C) S2D) S3E) S4F) S5G) All of the stages contain the same total charge. 33.) The substrates for the pentose phosphate shunt enzymes transketolase or transaldolase may contain a total of _____ carbon atoms for each individual reaction. A) 3B) 5C) 7D) 9E) 10F) 12G) D or E 34.) The major metabolite regulating the activity of glycogen phosphorylase is _____ in liver cells, and _____ in muscle cells. A) glucose / ATPB) AMP / ATPC) ATP / glucoseD) UTP / AMP E) insulin / Ca2+F) UTP / CTPG) glucagon / insulin 35.) If glucose-6-phosphatase was erroneously abundantly expressed in muscle cells, which of the following effects would occur? A) elevated blood concentration of glycogenB) elevated blood concentration of cholesterol C) elevated blood concentration of epinephrineD) lowered blood concentration of bicarbonate E) decreased concentration of ATP in the muscle cytoplasmF) all of the aboveG) none of the above 36.) Effectively, how many protons of the gradient across the chloroplastic inner membrane are depleted when ATP synthase completes one full turn (360°) forming molecule(s) of ATP and relocating it(them) to the cytoplasm? A) 0B) 3C) 4D) 6E) 9F) 12G) 14 Biochemistry CHEM 3500Summer 2020Exam 4Name: ______________________________ Dr. Meades 36 possible pointsFor questions 1-36, choose the one best answer (1 point each). You may keep the exam questions. TURN IN THIS PAGE ONLY Print, fill out by hand, take photo or scan ensuring choices can be read clearly, and email image/pdf of this answer sheet to:
[email protected] before 6:15pm. Late or non-hand written submissions will not be accepted.