This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond Chapter 4 Amino Acids and the Peptide BondMULTIPLE CHOICE1 The intrinsic properties of the 20 amino acids include all EXCEPT a Carbon is symmetric b The capacity to polymerize c Novel acid base properties d Varied structure and chemical functionality in side chains e ChiralityANS APTS 12 The amino and carboxyl groups of amino acids react in a head to tail fashion eliminating water and forming a covalent linkage typically referred to as a n bond a ester aromaticb anhydride phosphoanhydridec amide peptided dehydration hydrogene none of the aboveANS CPTS 13 Because peptide bond formation is thermodynamically biological systems must couple peptide bond formation to a thermodynamically reaction a favorable favorableb unfavorable unfavorablec favorable unfavorabled unfavorable favorablee none of the aboveANS DPTS 14 All of the statements about the classification of these amino acids are correct EXCEPT a Aspartic acid and asparagine are acidic amino acids b Alanine and valine are neutral nonpolar amino acids c Serine and glutamine are polar uncharged amino acids d Lysine and arginine are basic amino acids e Tyrosine and phenylalanine are aromatic amino acids ANS APTS 15 The difference between serine and homoserine is the same as between cysteine and homocysteine Thischange from the common amino acid is a one additional methylene CH2 group b one additional carboxyl group c two additional amine groups d presence of a ring system e one additional amine group ANS APTS 1Garrett Grisham 5eTest Bank1 This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond 6 Which of the following amino acids has more than one chiral carbon a serineb lysinec threonined cysteinee aspartic acidANS CPTS 17 Which of the listed amino acids is classified as a basic amino acid a leucineb phenylalaninec aspartated asparaginee lysineANS EPTS 18 All of the amino acids EXCEPT have both free amino and free carboxyl groups a aspartic acidb prolinec asparagined lysinee valineANS BPTS 19 The amino acid with a side chain pKa near neutrality and which therefore plays an important role as proton donor and acceptor in many enzyme catalyzed reactions is a histidine b cysteine c proline d serine e methionine ANS APTS 110 The pKa of the carboxyl group of an amino acid is by the presence on the amine group a greatly increased 2 pH units b greatly decreased 2 pH units c unchangedd slightly increased 1 2 pH units e slightly decreased 1 2 pH units ANS BPTS 111 Which statement about these amino acids and amino acid derivatives is correct a GABA aminobutyric acid is a potent inhibitory neurotransmitter derived from aspartic acid b Ornithine is an important metabolic intermediate found in the urea cycle c Epinephrine is a hormone derived from tryptophan d Serotonin is a neurotransmitter derived from tyrosine e Histamine is a neurotransmitter derived from glutamine ANS BPTS 1Garrett Grisham 5eTest Bank2 This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond Garrett Grisham 5eTest Bank3 This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond 12 At which of the following pH values would histidine pKa values of 1 8 6 0 and 9 2 be found with a net negative charge a 1 0b 4 0c 8 0d 11 0e none of the aboveANS DPTS 113 What is the pH of a serine solution in which the amine group pKa 9 2 is 33 deprotonated a 8 7b 8 9c 9 0d 9 5e 9 8ANS BPTS 114 Glutamic acid has pKa values of 2 2 4 3 and 9 7 Calculate the isoelectric point for glutamic acid a 3 25b 4 3c 5 4d 7 0e 8 6ANS APTS 115 If the pI of a peptide is 4 6 might be present while would probably be absent a Glu Lysb His Serc Arg Hisd Asp Glye Cys TyrANS APTS 116 An amino acid an aldehyde water a amide b ester c substituted amide d hemiacetal e Schiff base ANS EPTS 117 The pKa of the cysteine side chain group is 8 32 so it is about 11 deprotonated at pH a acid 3 2b amino 8 5c hydroxyl 10 2d sulfhydryl 7 4e none of the aboveANS DPTS 1Garrett Grisham 5eTest Bank4 This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond 18 Ninhydrin has all these properties EXCEPT a It reacts with an amino acid by oxidatively deaminating its amino group b It can be used to detect the location of amino acids following chromatography c It produces a purple colored product upon reaction with alanine d It produces a yellow product upon reaction with histidine e It can be used to quantify most amino acids ANS DPTS 119 All of the following react with the thiol group on cysteine EXCEPT a N ethylmaleimide b iodoacetate c acrylonitrile d Ellman s Reagent e benzaldehyde ANS EPTS 120 Which of the peptides would absorb light at 280 nm a Ala Lys Hisb Ser Gly Asnc Ala Ala Trpd Val Pro Leue Ser Val IleANS CPTS 121 Which of the following amino acids absorbs light most strongly between 250 and 300 nm a Hisb Phec Trpd Tyre None of the above absorb light in this rangeANS CPTS 122 All are true for stereoisomers EXCEPT a A diastereomer is a nonsuperimposable non mirror image b An enantiomer is a nonsuperimposable mirror image c Diastereomers have different melting points d Diastereomers rotate plane polarized light in equal but opposite directions e None all are true ANS DPTS 123 All are true statements about L isoleucine EXCEPT a Its enantiomer is named D isoleucine b L alloleucine would be its diastereomer c It contains a total of two asymmetric or chiral carbons d It can also be named as 2S 3S isoleucine using the R S system e Its diastereomer would be named D leucine ANS EPTS 1Garrett Grisham 5eTest Bank5 This study source was downloaded by 100000798215777 from CourseHero com on 02 14 2022 15 31 08 GMT 06 00 https www coursehero com file 9203706 CH 4 Amino Acids and Peptide Bond 24 Using a cation exchange resin a mixture of four amino acids is separated using an elution gradient of increasing NaCl solution What would be the correct elution sequence a Asp Arg Ser Lysb Arg Asp Lys Serc Lys