8/16/2019 G&G5e_TB_CH05

1/8

Chapter 5—Proteins: Their Primary Structure and Biological Functions

MULTIPL C!"IC

1. A gene can be defined as:

a. the unique function that some cells have but other cells do not have.b. a specific segment of nucleotide bases in DNA that encode for the synthesis of a particular

protein.c. a single strand of DNA that is designated as the sense strand.

d. a functional segment of a unique protein.e. the segment of DNA that is changed in a mutation.

ANS: B PS: 1

!. Proteins "ith t"o different polypeptide chains are:a. monomeric proteins.

b. trimeric proteins.c. homodimeric proteins.d. heterodimeric proteins.e. none of the above.

ANS: D PS: 1

#. $emoglobin is an !% ! &&&& "hereas% glutamine synthatase from E. coli is an ! &&&&.a. 'homodimer% 'homomultimerb. 'heteromultimer% 'homomultimerc. 'homomultimer% 'heterodimer

d. 'heterodimer% 'monomeric proteine. 'heterodimer% 'homomultimer

ANS: B PS: 1

(. )ibrous proteins% such as collagen% have "hich one of the follo"ing properties*a. $ighly soluble in "ater.

b. heir hydrophilic residues are directed into the interior of the protein.c. +,hibit en-ymatic activity.d. Serve structural roles in the cell.e. onomeric.

ANS: D PS: 1

/. 0hich of the follo"ing S N2 a characteristic of globular proteins*a. nsoluble in "ater.b. 3oughly spherical.c. )olded so that the hydrophobic amino acids are in the interior of the molecule.

d. $ydrophobic side chains are e,posed to the "ater.e. None% all are true.

ANS: A PS: 1

Garrett/Grisham 5e Test Bank 1

8/16/2019 G&G5e_TB_CH05

2/8

4. olecules of a given protein have all +56+P:a. a fi,ed amino acid composition.

b. a defined amino acid sequence.c. a sequence read from 6'terminal end to N'terminal end.

d. an invariant molecular "eight.e. a nucleotide sequence from "hich they are encoded.

ANS: 6 PS: 1

7. embrane proteins differ from globular proteins in that:a. membrane associated amino acids usually have polar side chains.

b. membrane proteins are much more soluble in detergents than "ater.c. membrane proteins usually have more hydrophobic amino acids.

d. globular proteins are "ater insoluble.e. All are true.

ANS: B PS: 1

8. A common reaction of t"o cysteine residues in proteins results in the formation of &&&&.a. thioester bonds

b. disulfide bondsc. dithiol bondsd. thioether bondse. none of the above

ANS: B PS: 1

9. he amino acid sequence is defined as &&&& structure.a. primaryb. secondaryc. tertiary

d. quaternarye. all are true

ANS: A PS: 1

1.   '$eli, and 'strand are components of &&&& structurea. primary

b. secondaryc. tertiaryd. quaternarye. all are true

ANS: B PS: 1

11. All of the information necessary for a protein to achieve its intricate architecture is contained "ithin its &&&& structure.a. primaryb. secondary

c. tertiaryd. quaternarye. all are true

ANS: A PS: 1

Garrett/Grisham 5e Test Bank 2

8/16/2019 G&G5e_TB_CH05

3/8

1!. he formation of a disulfide bond "ould be an e,ample of "hat level of protein structure*a. primary

b. secondaryc. tertiary

d. quaternarye. both c and d are correct

ANS: + PS: 1

1#. 0hich of the follo"ing S N2 a characteristic of a protein;s overall conformation*a. he overall three'dimensional architecture of the protein.

b. Achieved by brea

8/16/2019 G&G5e_TB_CH05

4/8

18. he amino acid sequence is N2:a. a distinctive characteristic of a polypeptide.

b. encoded by the nucleotide sequence of DNA.c. a form of genetic information.

d. read from N'terminal end to 6'terminal end.e. constant for proteins "ith the same function from different organisms.

ANS: + PS: 1

19. +dman degradation "ill:a. determine the 6'terminal amino acid by using a carbo,ypeptidase.

b. cleave the protein into a multitude of smaller peptides.c. compare overlapping sets of peptide fragments.

d. determine the N'terminal amino acid.e. generate t"o different% but overlapping sets of peptide fragments.

ANS: D PS: 1

!. After treating a protein "ith trypsin% "hich of the follo"ing techniques could be used to determine itsidentity by peptide mass fingerprinting*

a. N3b. A@D'2) mass spectrometerc. $P@6d. gel electrophoresis

e. none of the above

ANS: B PS: 1

!1. 3eaction of the peptide% ala'met'lys'ser% "ith phenylisothiocyanate =P6? at p$ 8. follo"ed by mildacidification =first cycle of +dman method? "ould release:a. the labeled peptide ala'met'lys'ser'P$.

b. P$'ala% P$'ser% P$'lys and P$'met.c. P$'ser and the peptide ala'met'lys.d. P$'ala and the peptide met'lys'ser.

e. All of the above.

ANS: D PS: 1

!!. 0hat is the product formed from the acid hydrolysis of a simple amide*a. acid baseb. aldehyde alcoholc. acid amine

d. ester alcohole. amine aldehyde

ANS: 6 PS: 1

!#. 0hich of the follo"ing "ould not be a useful procedure for dissociating the subunits of a multimericprotein in order to sequence the individual subunits*

a. +,posure to p$ e,tremes =ie% p$ 1 or p$ 1#?.b. $igh salt concentrations.c. 4 N  $6l at 116 for !( hours.d. 8 urea.

e. 4 guanidinium chloride.

ANS: 6 PS: 1

Garrett/Grisham 5e Test Bank 4

8/16/2019 G&G5e_TB_CH05

5/8

!(. nsulin is a polypeptide hormone that contains t"o short polypeptide chains lin

8/16/2019 G&G5e_TB_CH05

6/8

!9. All of the statements about the peptide val'asp'trp'asn'ser are correct +56+P:a. his peptide "ould sho" a strong absorption band at !8 nm.

b. 3eaction "ith chymotrypsin "ould yield t"o peptides.c. o synthesi-e this peptide using the solid phase method of errifield% the amino acid

directly attached to the resin "ould be valine.d. After the second round of +dman degradation using the reagent P6% the P$'amino

acid residue released "ould be P$'asp.e. he peptide "ould be converted to a dipeptide and a tripeptide by chymotrypsin.

ANS: 6 PS: 1

#. 0hich of the follo"ing "ould be a possible amino acid sequence for an oligopeptide given thee,perimental data belo"*

1. he amino acid composition is found to be Cala% lys% phe% met% cys% plus somedecomposition products.

!. he peptide has a molecular "eight around 7 Da and absorbs at !8 nm.

#. reatment "ith carbo,ypeptidase results in tryptophan and a peptide.(. 6NBr treatment yields a tetrapeptide and a dipeptide./. rypsin digestion produces an amino acid and a pentapeptide "ith met on the amino end.4. 6hymotrypsin digestion yields a dipeptide and a tetrapeptide.

a. trp'lys'met'cys'met'alab. lys'met'cys'phe'ala'trpc. trp'ala'phe'cys'met'lys

d. lys'ala'cys'phe'met'trpe. lys'met'cys'ala'phe'trp

ANS: B PS: 1

#1. he preponderance of protein sequence information is no" derived from:a. chemical sequencing =+dman method?.

b. mass spectrometry.c. mass spectrometry'mass spectrometry.

d. translating the nucleotide sequence of genes into codons% and thus amino acid sequence.e. none of the above.

ANS: D PS: 1

#!. $omologous proteins such as hemoglobin from different organisms do N2:a. have nearly identical lengths.b. share little sequence homology "ith other proteins "ith similar function =e.g.% myoglobin?.c. share a significant degree of sequence similarity.

d. perform the same function in different organisms.e. have sequence identity in direct correlation to the relatedness of the species from "hich

they "ere derived.

ANS: B PS: 1

Garrett/Grisham 5e Test Bank 6

8/16/2019 G&G5e_TB_CH05

7/8

##. Although they have very different functions% hen egg "hite lyso-yme and &&&& share similar sequencehomology and similar tertiary structure.

a. trypsinb.   'lactalbuminc. thrombind. hemoglobin

e. chymotrypsin

ANS: B PS: 1

#(. he diversity in hemoglobin mutants indicates that:

a. any amino acid change is relatively important.b. any amino acid change is lethal to the organism.

c. specific amino acid changes drastically alter one or more functions of a protein.d. any amino acid change "ill have the same effect on the protein function.

e. All are true.

ANS: 6 PS: 1

#/. Proteins destined for an e,tracellular location are characteristically:a. phosphoproteins.

b. glycoproteins.c. lipoproteins.d. nucleoproteins.

e. flavoproteins.

ANS: B PS: 1

#4. Proteins that do N2 perform any obvious chemical transformation% but control the ability of other

proteins to carry out their physiological functions are:a. en-ymes.

b. regulatory proteins.c. transport proteins.d. storage proteins.

e. structural proteins.

ANS: B PS: 1

#7. $emoglobin is an e,ample of a=n?:a. en-yme.b. regulatory protein.c. transport protein.

d. storage protein.e. structural protein.

ANS: 6 PS: 1

#8. 6ollagen is an e,ample of a=n?:a. en-yme.

b. regulatory protein.c. transport protein.d. storage protein.e. structural protein.

ANS: + PS: 1

Garrett/Grisham 5e Test Bank 7

8/16/2019 G&G5e_TB_CH05

8/8

#9. he lac repressor is an e,ample of a=n?:a. en-yme.

b. regulatory protein.c. transport protein.

d. storage protein.e. structural protein.

ANS: B PS: 1

(. 0hich of the follo"ing reagents is correctly defined*a. iodoacetic acid: reduces disulfide bonds

b. guanadinium hydrochloride: disrupts ionic interactions and hydrogen bondsc. phenylisothiocyanate: reacts "ith free carbo,yl groups

d. cyanogen bromide: reacts "ith internal cysteine residuese. performic acid: reacts "ith free cysteine residues

ANS: B PS: 1

(1. 0hich of the follo"ing protease en-ymes is correctly identified "ith its specificity*a. trypsin: cleaves on 6'side of acidic amino acids

b. chymotrypsin: cleaves on 6'side of aliphatic amino acidsc. staphylococcal protease: cleaves on 6'side of acidic amino acidsd. clostripain: cleaves on 6'side of lysinee. none of the above are correct

ANS: 6 PS: 1

(!. 0hich of the follo"ing amino acids occurs most frequently in proteins*a. methionineb. alaninec. tryptophan

d. tyrosinee. histidine

ANS: B PS: 1

(#. 0hich of the follo"ing mutations "ould probably be least li