bchem EOY 2014 — Past Paper Questions & Answers

Biochemistry EOY 2014 — Visual Scan Archive All 13 source pages are included. The scan contains diagrams, handwritten/photographic content or pages with too little reliable machine-readable text for a safe flattened question sequence. Original page images are therefore the authoritative paper; usable OCR labels are preserved below. i Scanned by CamScanner ee Scanned by CamScanner Scanned by CamScanner Scanned by CamScanner : 4. : [Statement «dt Answer — (i) Name a ‘stop’ code for protein U AG UGh U0 Ak. biosynthesis ! (ii) The enzyme that lays an RNA primer in DNA replication/ (iii) The enzyme that makes a double stranded DNA from a single strand RNA template in viral replication (iv) Translocase in protein biosynthesis is ) also referred to as (v A compound that inhibits transcription (vi) Name three post-transcriptional modifications in eukaryotes: Ee ee 3 =. - (viii) Name two types of post-translational modifications on OH containing amino acid proteins oF Urea cycle begin inside mitochondria where carbamoyl Phosphate donate its carbamoyl group to ornithine to form = . The reaction is catalyzed by , and the product passes form the to the The second amino group then enters the cycle by a condensation reaction between the amino groups of and ureido group of citrulline, forming in areaction catalyzed by —————s—i‘CS the product is then cleaved bythe enzyme to form fumarate and . In the last reaction of the urea : cleaves cycle, the cytosolic enzyme Ee —— EEE 5 to yield urea and ornithine. j 4 Scanned by CamScanner aa ma — — EFg LLLLLLLLLLLL LL . & & ; foe many molecules of ATP are synthesized per NADH oxidized? pte ee Die G1 D. 4 hes E. 5 ae How many, ATPS are produced by oxidation of molecule of acetyl CoA ? . Ae wet i = pe = 7A 1 } 1Z = z Nes ‘ 14 CLP, BE. 16 (cling . = A kinase is an enzyme that; — ee A. Uses NADH to change the oxidation state of a substrate B. Uses ATP to fix.a carbon to a substrate C. Removes water from a double bond Dy, Removes phosphate groups of substrates , A @ Uses ATP to add a phosphate group to a substrate ; 6. Inthe glycogen synthase reaction, the precursor to glycogen is; as A. G6P . GIP f <UDP-glucose = ae = 94009 actly i . UTP-glucose E. CDP-glucose glace qe 3. Pyruvate is initially converted to which of the following in gluconeogenesis? s A. Glycerol ee Se OAA ) . AcetylCoA E. Lactate : } 2 \\ \ ets we, Ae ie wai loge (ea Wet ¥ j ye Ce Na \ A. Depurination / ae Sls Ree ye? : 5 oan Qaatonndsae, Arr te eg Se Thymine dimerization Loss of pyrimidine bases D. covalent linkage between adjactnt SUERE facleotides E. None of the above i 6 Scanned by CamScanner @ ® SS eee @ . @ , ® © Scanned by CamScanner (4 : © @ Scanned by CamScanner A Batng starvation, alanine transports amino group to the liver in a non-toxic form, : de via a pathway called: A. Cori cycle(tackebe) B. Citric acid cycle C. Ureacycle i oO" Glucose-alanine cycle Clase (hw uct) . Glyoxylate cycle 28. The structural integrity of supramolecular complexes are bonded to each other by all of the following forces, EXCEPT: A. covalent bonds B. van der Waals forces ® hydrogen-bonds . hydrophobic interactions . ionic interactions } 29. What is the nucleotide sequence of the DNA strand that is complementary to -ATCGCAACTGTCACTA-3;? ’ @ 5’-TAGCGTTGACAGTGAT-3’ i p B. 5S-UAGUGACAGUUGCGAU-3’ C. 5’-TAGCGTTGACAGTGAT-3’ D. 5’-TAGTGACAGTTGCGAT-3’ E. 5’-ATCACTGTCAACGCTA-3’ : -30. In the classification of amino acids, A. Aspartic acid and asparagine are acidic amino acids. B. Alanine and valine are polar amino acids C. Serine and glutamine are non polar, uncharged amino acids. : f ® Lysine and arginine are basic amino acids Tyrosine and phenylalanine are branched chain amino acids f 31. When preparing an acetate buffer at pH 4.5 with 0.01 M solutions of acetic acid ) (pK.=4.8) and sodium acetate, the volume of acetic acid needed would be F the volume of sodium acetate solution Dion; A. equalto . “a B. less than half of 7 C. more than half of D. about six times E. about twice ’ a el 10 us 6 ® 4 © 6 Scanned by CamScanner eT ee LETC rrrLCULreTCS—“‘=#EEENNNCCNCCC'iéasttdsatit#t. © &