MT2+SS1+2011+WRITTEN+KEY - BIS 103 SS1 2011...

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Unformatted text preview: BIS 103 SS1 2011 MIDTERM 2 INSTRUCTOR: ME WEGNER Written Answer (Questions 22 ­30) NAME___________________________________________ 22. (15 pts) The TCA Cycle, listed below, is missing several items, each specified by a box (8 boxes) or line (7 lines). Fill in the structures for major products and reactants, cofactors/coenzymes names, or enzymes names when appropriate. (SEE TCA CYCLE IN NOTES/BOOK FOR ANSWERS) PAGE POINT TOTAL__________/15 1 23. (10pt) Diagram below the hormonal regulation of fatty acid synthesis including all substrates, products, cofactors, enzymes names, and covalent modification (methyl, phosphate etc.) and arrow directions (NO ABBREVIATIONS). Circle INCREASE or DECREASE where appropriate. H2O Pi INSULIN P Protein Phosphatase AcetylCoA Carboxylase Protein Kinase AcetylCoA Carboxylase Vitamin derived cofactor:___Biotin_________ Increase or decrease of fatty acid synthesis ADP ATP Increase or decrease fatty acid synthesis EPINEPHRINE 24. (3 pts) Considering the list of standard reduction potentials for the biological half ­reactions below, which molecule is the best oxidizing agent under standard ­ state conditions? WRITE ANSWER IN BOX BELOW REACTIONS. E’o acetate + 3 H+ + 2 e ­  acetaldehyde + H2O  ­0.68 oxaloacetate + 2 H+ + 2 e ­  malate  ­0.19 fumarate + 2 H+ + 2 e ­  succinate  ­0.04 FUMARATE 2 PAGE POINT TOTAL__________/13 25. (6 pts) The synthesis of 1 mole of ATP was driven by the translocation of 2 moles of H+ into the mitochondria. The membrane potential (ΔΨ; inside relative to outside) across the mitochondrial membrane was  ­0.162 V. What would the ΔpH (pHin ­pHout) be to drive the synthesis of ATP? Assume that the non ­standard state of ΔG of ATP synthesis (ADP + Pi  ATP HOH) is +45,000 j/mole. SHOW ALL WORK IN BOX BELOW. ΔG ATP syn + ΔG H+ Flux = 0 45,000 + ΔG H+ Flux = 0 ΔG H+ Flux = 45,000 J/mol ATP (1mol ATP/2mole H+) =  ­22,500 (this is the energy available) ΔG H+ Flux = z F Δψ  ­ 2.3 RT ΔpH  ­22,500 = (1) (96,496)( ­0.162) – 2.3 (8.314)(298) ΔpH ΔpH = 1.2 26. (4 pts) Tetrapyrrole compounds in plants are derived from the TCA cycle intermediate _____alpha ­keto glutarate___ , however terrapyrroles in animals are derived from ______succinyl ­CoA______, also a TCA cycle intermediate. 3 PAGE POINT TOTAL_________/10 27. (4 pts) Identify the synthetic pathway affected in Phorhyrias patients, the cause, physiologic outcomes and treatment. Synthetic Pathway:_____HEME SYNTHESIS _____ Cause:__Defect in enzymes in the heme synthesis pathway _____ Physiologic outcome: sun sensitivity / red skin / fluorescent teeth / anemia/ red urine Treatment:_______Heme supplementation / injection ______ 28. (8 pts) (PARTS A and B) A. When liver mitochondrial oxaloacetate concentrations become low in a 500 ­ pound tiger hunting in the jungles of Sumatra, excess of _________Kentone Bodies___ may be formed as the result of fatty acid degradation. B. Draw out the structures and name the major reactants and products of the final step in the synthesis of the primary physiologic compound synthesized in part A in the box below: (no abbreviations) NADH H+ NAD+ Beta ­hydroxybutarate Acetoacetate Dehydrogense *see notes for structures 4 PAGE POINT TOTAL__________/12 29. (6 pts) The NET maximum yield of ATP per mole of lauritoyl ­S ­CoA (12:0), the primary fatty acid in coconut oil, when oxidized completely to carbon dioxide and water is: SHOW ALL WORK IN BOX FOR CREDIT. Beta ­Ox: 5 cycles 5x 1 NADH = 5 x 3 = 15 ATP 5 x 1 FADH2 = 5 x 2 = 10 ATP 25 ATP from beta ox 6 Acetyl ­CoA formed TCA: 6x 3 NADH = 18 NADH x 3 = 54 ATP 6x 1 FADH2 = 6 FADH2 x 2 = 12 ATP 6x 1 GTP = 6 GTP x 1 = 6 ATP 72 ATP from TCA 25 + 72 = 97 ATP *note this FA was already activated 30. (2 pts) The first reaction in the complete oxidation of the fatty acid below would most likely be (CIRCLE ONE) DECARBOXYLATION CLEAVAGE TO PROPIONIC ACID DEMETHYLATION THIOESTER FORMATION α  ­OXIDATION PAGE POINT TOTAL_________/ 8 5 6 ...
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This note was uploaded on 08/02/2011 for the course MCB 103 taught by Professor Molliewegner during the Spring '11 term at UC Davis.

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