Sample/practice exam 2019, questions and answers PDF

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CHEM EXAM PRACTICE...

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Exam 4A

Chem 1152 Sp 2016 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The removal of 2-carbon segments of a fatty acid for further metabolism is called 1) _______ A) dehydration. B) deglyceration. C) β oxidation. D) decarboxylation. E) transamination. 2) Myristic acid, a fatty acid, produces __________ acetyl CoA when completely metabolized. 2) _______ A) 7 B) 2 C) 14 D) 5 E) 12 3) All the acetyl CoA produced in the body goes as the starting material into ____________ 3) _______ A) Urea cycle B) Citric acid cycle C) gluconeogenisis D) None of the above 4) In the first reaction of the citric acid cycle 4) _______ A) NADH is produced. B) glucose becomes pyruvate. C) pyruvate becomes C and O. D) acetyl CoA reacts with oxaloacetate to give citrate. E)

ATP is produced. 5) When oxygen is in plentiful supply in the cell, pyruvate is converted to 5) _______ A) CoA. B) fructose. C) acetyl CoA. D) lactate. E) glucose. 6) In citric acid cycle ____ CO2 molecules are formed 6) _______ A) 1 B) 2 C) 3 D) 4 7) In electron transport, the synthesis of ATP from ADP + is called 7) _______ A) fermentation. B) isomerization. C) glycolysis. D) oxidative phosphorylation. E) hydrolysis. 8) Overall, catabolic reactions 8) _______ A) release energy. B) take in energy. C) take place in the nucleus of the cell. D) occur mainly in the liver. E) occur outside the cell membrane.

9) Gluconeogenisis reaction can be classified as a _____________ process 9) _______ A) anabolic B) catabolic C) phosphorylation D) oxidative 10) The main compound used to release energy for metabolism is 10) ______ A) ribonucleic acid. B) adenosine triphosphate. C) sucrose. D) NA. E) glucose phosphate. 11) stands for the coenzyme 11) ______ A) nicotinamide diphosphate. B) niacin adenine dinucleotide. C) nicotinic acid diphosphate. D) nicotinamide adenine dinucleotide. E) nicotine adenosine dinucleotide. 12) In the process of glycolysis, glucose is converted to 12) ______ A) ribose. B) sucrose. C) oxaloacetate. D) pyruvate. E) citrate.

13) The synthesis of glycogen from glucose is called 13) ______ A) glyceration. B) glycolysis. C) glycogenesis. D) gluconeogenesis. E) glucogenesis. 14) The general function of an enzyme in the body is to 14) ______ A) maintain homeostasis. B) catalyze chemical reactions. C) maintain a neutral pH. D) eliminate waste products from the blood. E) act as a reactant in carbohydrate storage. 15) In any reaction catalyzed by an enzyme, the reacting molecule is called the 15) ______ A) coenzyme. B) cofactor. C) isozyme. D) substrate. E) allostere. 16) ____________ are type of eznymes that catalyze reactions in glycolysis 16) ______ A) Isomerases B) Kinases C) dehydrogenases D) mutases 17)

Urease catalyzes only the hydrolysis of urea, and no other substrates. This limited activity is called 17) ______ A) hyperspecificity. B) rigid specificity. C) absolute specificity. D) extreme specificity. E) noncompetitive specificity. 18) In the lock-and-key model of enzyme action, the enzyme active site is thought of as 18) ______ A) a key-like shape that fits into a pocket of the substrate surface. B) an area of the enzyme that can adjust to fit the substrate shape. C) a hydrophilic area on the enzyme surface. D) a rigid, nonflexible shape that fits the substrate exactly. E) a lock that bars a noncompetitive inhibitor from reacting. 19) To what main class of enzymes does the enzyme that catalyzes the following reaction belong? O CO →

OH HCO

19) ______ A) lyase B) isomerase C) transferase D) oxidoreductase E) hydrolase 20) Most enzymes are deactivated permanently above a temperature of about 20) ______ A) 45 °F. B) 25 °C. C) 37 °F. D)

50 °C. E) 40 °C. 21) A competitive inhibitor is one that 21) ______ A) destroys the substrate. B) binds to the active site in place of the substrate. C) forms a complex with the substrate. D) binds to the allosteric site on an enzyme. E) binds to the enzyme at a site far from the active site. 22) Metal ions such as and are often needed by enzymes as 22) ______ A) cofactors. B) inhibitors. C) substrates. D) isozymes. E) allosteres. 23) Which of the following is found in RNA but not in DNA? 23) ______ A) thymine B) deoxyribose C) guanine D) cytosine E) uracil 24) The nucleotides in the backbone of DNA are held together by __________ bonds. 24) ______ A) ionic B) phosphodiester C) glycosidic

D) hydrogen E) peptide 25) When DNA replicates, a guanine forms a base pair with 25) ______ A) thymine. B) adenine. C) guanine. D) uracil. E) cytosine. 26) Which of the following is a section of mRNA produced from the DNA template below? 3'-A-T-A-G-C-T-A-5' 26) ______ A) 5'-U-U-U-G-C-U-U-3' B) 5'-T-A-T-C-G-A-T-3' C) 5'-A-T-A-G-C-T-A-3' D) 5'-U-A-U-C-G-A-U-3' E) 5'-A-U-A-G-C-U-A-3' 27) Translation is the process whereby 27) ______ A) DNA is synthesized from DNA. B) protein is synthesized from mRNA. C) mRNA is synthesized from DNA. D) protein is synthesized from DNA. E) DNA is synthesized from mRNA. 28) Which of the following is not a step in protein synthesis? 28) ______ A) elongation B) activation of tRNA

C) unwinding of two strands of mRNA D) initiation E) termination

1) C 2) A 3) B 4) D 5) C 6) B 7) D 8) A 9) A 10) B 11) D 12) D 13) C 14) B 15) D 16) B 17) C 18) D 19) D 20) D 21) B 22) A 23) E 24) B 25) E 26) D 27) B 28) C...